(a) A pentagon ABCDE has sides AE and CD parallel and the line EC
is parallel to side AB. Sides ED and BC, when extended, meet at a
point F. ZABC is equal to ZCDE. Show that ZAEC = ZCFD.
(b) If, furthermore, triangles EDC and DFC are both isosceles, with
ED = DC and DF = FC, find the angles of the pentagon.
Answers
(a) ∠AEC = ∠CFD, by transitive property of equality
(b) ∠CDE = 108°, ∠DCB = 108°, ∠ABC = 108°,∠EAB = 144°, ∠AED = 72°
The reason the above values are correct is as follows:
(a) The given parameters are;
Figure ABCDE is a pentagon
The sides AE is parallel to side CD
Line EC is parallel to side BC
The point of intersection of the extension off side ED and BC = Point F
∠ABC = ∠CDE
Required:
To show that ∠AEC = ∠CFD
Method:
Draw the pentagon ABCDE and include the added construction
Analyze the drawing
Solution:
∠ECF and ∠ABC are corresponding angles between parallel lines EC ║BC
∴ ∠ECF ≅ ∠ABC by corresponding angles formed by parallel lines are congruent
∠ECF = ∠ABC by definition of congruency
∠ABC = ∠CDE = ∠ECF by transitive property
∠ECD ≅ ∠AEC by alternate angles formed between parallel lines having a common transversal
∠ECD = ∠AEC by definition of congruency
∠ECF = ∠FCD + ∠ECD by angle addition postulate
∠CDE = ∠FCD + ∠CFD by exterior angle theorem
From ∠CDE = ∠ECF above, we have;
∠ECF = ∠FCD + ∠ECD = ∠FCD + ∠CFD
∴ ∠ECD = ∠CFD by addition property
∠ECD = ∠AEC, therefore;
∠AEC = ∠CFD, by transitive property
(b) Given that ΔEDC and ΔDFC are both isosceles triangles, with sides;
ED = DC, and DF = FC;
Let r represent ∠CFD, we have;
∠FCD = ∠CDF by base angles of isosceles triangle ΔDFC
∠ECD = ∠CED by base angles of isosceles triangle ΔEDC
∠AEG = ∠CDE by corresponding angles formed by parallel lines having a common transversal
∠AEC = ∠ECD by alternate angles
∴ ∠AEG + ∠AEC + ∠CED = 180° Sum of angles on a straight line
∠CDE = ∠CFD + ∠FCD
∠CDE + ∠CDF = 180° (linear pair angles)
∴ ∠AEG + ∠CDF = 180° by transitive property
∠AEC + ∠CED = ∠CDF by transitive property
∠AEC = ∠ECD = ∠CED = ∠CFD = r
∴ ∠CFD + ∠CFD = ∠CDF
2·r = ∠CDF
∠CDE = ∠FCD + ∠CFD
∠FCD = ∠CDF = 2·r
∴ ∠CDE = 2·r + r = 3·r
∠CDE = 3·r
The angles of the pentagon are;
∠CDE + ∠DCB + ∠ABC + ∠EAB + ∠AED = 540° sum of angles in a pentagon
∠DCB = 180° - ∠FCD
∠DCB = 180° - 2·r
∠ABC = ∠CDE = 3·r
∠EAB = ∠CEH corresponding angles
∠CEH = 180 - ∠AEC
∴ ∠EAB = 180° - ∠AEC
∴ ∠EAB = 180° - r
∠AED = ∠AEC + ∠CED = r + r = 2·r
∠AED = 2·r
Therefore, we have;
3·r + 180° - 2·r + 3·r + 180° - r + 2·r = 540°
5·r + 360° = 540°
r = (540° - 360°)/5 = 36°
r = 36°
∠CDE = 3 × 36° = 108°
∠DCB = 180° - 2×36° = 108°
∠ABC = 3 × 36° = 108°
∠EAB = 180° - 36° = 144°
∠AED = 2 × 36° = 72°
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Related Questions
In ΔOPQ, the measure of ∠Q=90°, OQ = 39, QP = 80, and PO = 89. What ratio represents the cosine of ∠P?
Answers
Answer:
The cosine of angle P = opposite / adjacent = 39 / 80
Step-by-step explanation:
You sunk my battleship...The hms petticoat and uss junction are being monitored on a tracking screen where each ship is measured in millimeters from the lower left corner. The linear path of the hms petticoat is given by y=2x+50. If x=3t, express y as a function of t minutes
Answers
Answer:
y = f(t) = 6t + 50
Step-by-step explanation:
Given:
y = 2x + 50
Where,
x = 3t
Substitute x = 3t into the equation
y = 2x + 50
y = 2(3t) + 50
Open parenthesis
y = 6t + 50
y = f(t) = 6t + 50
Can someone please help me with this?
Answers
Answer:
p = 1.2
Step-by-step explanation:
Bring 3.9 to the other side of the equation.
-10.9p = -13.08
p = 1.2
Please help I will mark brainliest- I already know it’s not the last two- please help!
Answers
Answer:
Traversable because it has exactly two odd nodes
Step-by-step explanation:
There is a rule that says it is traversable if it has exactly 2 odd nodes. The are other rule where it can be traversable is if has no odd nodes.
Also if we let the starting point be D and the ending point be B we can travel the network in such way that each edge is only traveled once which is the definition that the network is traversable.
So I will do this by starting at D, then travel to A using the outside edge, then travel to back to D using inside edge, then travel to C, then travel to B, then travel to A using outside edge, and then back to B from A using inside edge.
Jahlil is 6 inches shorter than 4 times his sister’s height. Jahlil’s height is 70 inches.
Answers
Answer:
x = his sister's height = 19 inches
Step-by-step explanation:
Let
x = his sister's height
Jahlil's height is given by the equation:
4x - 6 = 70
4x = 70 + 6
4x = 76
x = 76/4
x = 19 inches
x = his sister's height = 19 inches
Check:
4x - 6 = 70
4(19) - 6 = 70
76 - 6 = 70
70 = 70
help i’m so confused
Answers
Answer:
-27/7
Step-by-step explanation:
put x into the equation
Lim x->-5(((1)/(5)+(1)/(x))/(10+2x))=
correct answer 1/10x = -1/50
explain:
Answers
Given:
The limit problem is:
[tex]lim_{x\to -5}\dfrac{\dfrac{1}{5}+\dfrac{1}{x}}{10+2x}[/tex]
To find:
The value of the given limit problem.
Solution:
We have,
[tex]lim_{x\to -5}\dfrac{\dfrac{1}{5}+\dfrac{1}{x}}{10+2x}[/tex]
It can be written as:
[tex]=lim_{x\to -5}\dfrac{\dfrac{x+5}{5x}}{2(5+x)}[/tex]
[tex]=lim_{x\to -5}\dfrac{x+5}{5x}\times \dfrac{1}{2(5+x)}[/tex]
[tex]=lim_{x\to -5}\dfrac{1}{5x\times 2}[/tex]
[tex]=lim_{x\to -5}\dfrac{1}{10x}[/tex]
Applying limit, we get
[tex]lim_{x\to -5}\dfrac{1}{10x}=\dfrac{1}{10(-5)}[/tex]
[tex]lim_{x\to -5}\dfrac{1}{10x}=\dfrac{1}{-50}[/tex]
Therefore, the value of given limit problem is [tex]-\dfrac{1}{50}[/tex].
A bakery owner asked 150 customers to taste a new type of cookie and found that 60 people liked it's taste.
Answers
Answer:
yes
Step-by-step explanation:
Here is the complete question :
A bakery owner asked 150 customers to taste a new type of cookie and found that 60 people liked its taste. 40% of the surveyed customers like the taste of the cookie. Is it an example of descriptive statistics?
Descriptive statistics are used to summarise the features or characteristics of a data or sample. It provides information on the features of sample collected.
Types of descriptive statistics
1. Measures of central tendency :
They include mean, median and mode
Mode refers to a value that appears most frequently in a data set.
Median can be described as the number that occurs in the middle of a set of numbers that are arranged either in ascending or descending order
Mean is the average of a set of numbers. It is determined by adding the numbers together and dividing it by the total number
Mean = sum of the numbers / total number
2. Measures of variation : It includes range, standard deviation and variance
3. Measure of position ; percentile and quartiles
4. Measure of frequency : count, percentage
solve |6x+3| = 27 .....
Answers
Answer:
Step-by-step explanation:
The absolute value of a number is defined as the positive of either a positive or a negative number. By that I mean that
| 1 | = 1 and | -1 | = 1. Right?
We use that idea here. Either:
6x + 3 = 27 OR 6x + 3 = -27 and solve both equations.
6x = 24 so x = 4 OR
6x = -30 so x = -5
Choice D is the one you want.
The ratio of keepers to animals in the city zoo is 2 : 7. The table shows the current numbers of animals and keepers in the zoo. If 21 more animals are added, how many total keepers are needed to maintain the ratio of keepers to animals?
City Zoo
Number of Keepers Number of Animals
12 42
Answers
Answer:
18
Step-by-step explanation:
42+12= 63
63/7=9
9*2=18
Answer:
18
Step-by-step explanation:
plato/edmentum
Find the difference of the polynomials given below and classify it in terms of degree and number of terms.
Answers
Answer:
4th degree polynomial with 4 terms
Step-by-step explanation:
Given:
3n²(n²+ 4n - 5) - (2n² - n⁴ + 3)
Open parenthesis
= 3n⁴ + 12n³ - 15n² - 2n² + n⁴ - 3
Collect like terms
= 3n⁴ + n⁴ + 12n³ - 15n² - 2n² - 3
= 4n⁴ + 12n³ - 17n² - 3
Number 1 term is 4n²
Number 2 term is 12n³
Number 3 term is -17n³
Number 4 term is -3
The highest degree of the polynomial is 4th degree
Therefore,
The difference in 3n²(n²+ 4n - 5) - (2n² - n⁴ + 3) is
4th degree polynomial with 4 terms
Answer:
4th degree polynomial with 4 terms
Step-by-step explanation:
Which translation vectors could have been used for the pair of
figures?
Select each correct answer.
Answers
Which formulas can be used to find the surface area of a right prism where p is the perimeter of the base, h is the height of the prism, BA is the area of bases, and LA is the lateral area? Check all that apply.
A. SA = BA - LA
B. SA = p + LA
C. SA = BA + LA
D. SA = BA + ph
E. SA = 1 / BA + LA
Answers
Answer:
SA=BA+LA and SA=BA+ph
Step-by-step explanation:
I just looked it up
The correct formulas to find the surface area of a right prism are:
SA = BA + LA and SA = BA + ph.
Options (A), and (D) are the correct answer.
What is a prism?A prism is a three-dimensional object.
There are triangular prism and rectangular prism.
We have,
The correct formulas to find the surface area of a right prism are:
1)
SA = BA + LA, where SA is the total surface area, BA is the area of the two identical bases, and LA is the lateral area (the sum of the areas of all the rectangular sides).
2)
SA = BA + ph, where SA is the total surface area, B is the area of one base, p is the perimeter of the base, h is the height of the prism, and ph is the area of all the rectangular sides (the lateral area).
Therefore,
The correct formulas to find the surface area of a right prism are:
SA = BA + LA and SA = BA + ph.
Learn more about prism here:
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How many 2/3 are in 4 use the tape diagram
Answers
Please help me asap!
Answers
Answer:
Its 48
Step-by-step explanation:
subtract 69 and 56 from 173, what you have left is your answer
48
Step-by-step explanation:
total 176 subtract 69 and 58 since they are given.
176 - 69 -56 = 48
Jacob and sumalee each improved their yards by planting daylilies and geraniums. They bought their supplies from the same store. Jacob spent $107 on 11 daylilies and 4 geraniums. Sumalee spent $60 on 4 daylilies and 12 geraniums. Find the cost of one daylilies and the cost of one geranium.
Answers
Answer:
Daylily: $9
Geranium: $2
Step-by-step explanation:
1 daylily costs x.
1 geranium costs y.
11x + 4y = 107
4x + 12y = 60
Multiply the first equation by 3 and subtract the second equation from it.
29x = 261
x = 9
4x + 12y = 60
4(9) + 12y = 60
12y = 24
y = 2
Answer:
Daylily: $9
Geranium: $2
Answer:
1) Set up a system of equations. Assign each plant a variable. I used X for Daylillies and Y for Geraniums. In this case:
11x + 4y = 107
4x + 12y = 60
2) Get one variable by itsef. You can choose to either get the X or the Y by itself. For the sake of ease, I'll go with achieving X.
3) Using the equation 4x + 12y = 60, isolate the 4x.
4x = -12y + 60
4) Divide both sides by 4.
x = -3y + 15
5) X is isolated. Now plug in that isolated X into another remaining equation in order to isolate Y. Don't forget to combine like terms.
11(-3y + 15) + 4y = 107
-33y + 165 + 4y = 107
-29y + 165 = 107
-29y = -58
y = 2
6) You have your Y, which means that each Geranium costs $2 each. Now, you need to find X. Plug in Y into any of the first two equations that we started with.
4x + 12(2) = 60
4x + 24 = 60
4x = 36
x = 9
7) You now have both X and Y. Daylillies cost $9 each, and Geraniums cost $2 each.
8) You can double-check your answers by plugging in your final X and Y values into any of the first equations you wrote. If it comes out equal, it works.
can someone help me with this?
Answers
Answer:
-64 is the 26th number
it's an arithmetic sequence because the difference between the number is constant : -3
they are all -3 in difference
Step-by-step explanation:
an = a1 + (n-1)d
an = the nᵗʰ term in the sequence
a1=the first term in the sequence
d=the common difference between terms
-64 = 11 + (n - 1)-3
-64=11 -3n+3
-78 = -3n
n = 26
W=VI. Make V the subject of formula
Answers
Answer:
hope that is helpful
Step-by-step explanation:
W= VI
W= VI
I. I
V= W
I
Answer:
V = [tex]\frac{W}{I}[/tex]
Step-by-step explanation:
Given
W = VI ( isolate V by dividing both sides by I )
[tex]\frac{W}{I}[/tex] = V
If Wade has 2 times as many dimes as quarters and they have a combined value of 270 cents, how many of each coin does he have?
Answers
Answer:
Step-by-step explanation:
If he has twice the number of dimes as quarters, then obviously he has more dimes than quarters. The expression that represents that is
d = 2q
That relates the NUMBER of coins; now we need one that relates the VALUE which is a dollars and cents thing. We know that the combined value of the coins is $2.70. The expression that represents this is
.1d + .25q = 2.70 because dimes are worth .10 and quarters are worth .25
Subbing the first equation into the second gives us
.1(2q) + .25q = 2.70 and
.2q + .25q = 2.70 and
.45q = 2.70 so
q = 6
This means he has 6 quarters. If the umber of dimes is twice as much, then d = 2(6) and d = 12.
He has 6 quarters and 12 dimes
Joshua is 1.45 meters tall. At 2 p.m., he measures the length of a tree's shadow to be 31.65 meters. He stands 26.2 meters away from the tree, so that the tip of his shadow meets the tip of the tree's shadow. Find the height of the tree to the nearest hundredth of a meter .
Answers
Answer:
height of the tree ≈ 8.42 m
Step-by-step explanation:
The diagram given represents that of two similar triangles. Therefore, the corresponding lengths of the similar triangles are proportional to each other.
height of tree = h
Therefore:
1.45/h = (31.65 - 26.2)/31.65
1.45/h = 5.45/31.65
Cross multiply
h*5.45 = 1.45*31.65
h*5.45 = 45.8925
h = 45.8925/5.45
h ≈ 8.42 m (nearest hundredth)
A jug holds 10 pints of milk. If each child gets one cup of milk, it can serve children. (Hint: 1 cup = 8 fluid ounces and 1 pint = 16 fluid ounces.)
Answers
Answer:
20 children
Step-by-step explanation:
We can see that 1 pint is equal to 2 cups. Since the jug holds 10 pints of milk, we can convert that to cups by multiplying by 2. We realize that the jug holds 20 pints of milk.
Since each child needs one cup of milk to be satisfied, we can state that the jug can satisfy 20 children.
Answer:
20 childrenyjvvvvggguggggyg
Find the measure of the indicated side
Answers
Answer: X = 8
Step-by-step explanation:
A bag contains 13 blue marbles, 12 red marbles, 6 yellow marbles, and 8 green marbles. What is
the probability of picking a red marble, putting that one back and then picking another red
marble?
4. Assume you have the same bag of marbles as the previous question. What is the probability of
selecting a yellow marble, then another yellow marble, then a red marble, and finally another
yellow marble, without replacing in between?
Answers
Answer:
12 in 29. uou add all the number together then and it is 12 red marbles in 29 chancesso you take one marble out and put the exact marble back in having no effect.
find the volume of the rectangular prism. plz answer this lol
Answers
Answer:
.....how when the dimensions are not even clear lol
Answer:
48 cm³
Step-by-step explanation:
the volume of a rectangular prism= length × breadth × height
= 8× 3 × 2
= 48 cm³
3 + 5 . (-3)=
5 . ( - 6 + 2 ) - 4=
- 5 + 8 . 2 + 1=
4/6 + 13/6 - 5/6=
2 . 8 - 5 . (3 - 4)=
7/3 . 5/2=
Answers
Step-by-step explanation:
PEMDAS rule
3 -15 = -12
-20 - 4 = -24
-5 + 16 + 1 = 12
= 12/6 which = 2
15 + 5 = 20
35/6 = 5 5/6
if the equation x^2 +(k+2)x+2k=0 has equal roots,then the value of k is .....a.2 b.-2 c 1/2 d.none
Answers
Answer:
k=2
Problem:
if the equation x^2 +(k+2)x+2k=0 has equal roots,then the value of k is ..
Step-by-step explanation:
Since the coefficient of x^2 is 1, we can use this identity to aid us: x^2+bx+(b/2)^2=(x+b/2)^2.
So we want the following:
[(k+2)/2]^2=2k
Apply the power on the left:
(k+2)^2/4=2k
Multiply both sides by 4:
(k+2)^2=8k
Expand left side:
k^2+4k+4=8k *I used identity (x+c)^2=x^2+2xc+c^2
Subtract 8k on both sides:
k^2-4k+4=0
Factor using the identity mentioned a couple lines above:
(k-2)^2=0
Since zero squared is zero, we want k-2=0.
Adding both sides by 2 gives k=2.
Expansion (2x-3y+4z)^2
Answers
Answer:
Step-by-step explanation:
(a+b+c)²=a²+b²+c²+2ab+2bc+2ca
(2x-3y+4z)²=(2x)²+(-3y)²+(4z)²+2(2x)(-3y)+2(-3y)(4z)+2(4z)(2x)
=4x²+9y²+16z²-12xy-24yz+16zx
We know that,
→ (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca
Now Putting 2x = a, -3y = b and 4z = c , we get
→ (2x - 3y + 4z)²
→ (2x)² + (- 3y)² + (4z)² + 2 × 2x × (- 3y) + 2 × (- 3y) × 4z + 2 × 4z × 2x
→ 4x² + 9y² + 16z² - 12xy - 24yz + 16zx
Arranging according to the like terms, we get
→ 4x² - 12xy + 16zx + 9y² - 24yz + 16z²
▬▬▬▬▬▬▬▬▬▬▬▬pls help- the question kept cutting off before:
If cos(πr) = 2 cos(πr) and 0 < r < 3, what is one possible value of r?
Answers
Answer:
r can be 0.5
Step-by-step explanation:
Here, we want to get a possible value of r
From the question, the value of r is between 0 and 3
Mathematically, we know that in degrees pi is the same as 180 degrees
In a case where we have r = 1/2
we have it that;
cos(pi/2) = 2 cos (pi/2)
Since pi/2 is 90 and cos 90 is zero; then we have it that the two sides of the equation is the same and r can be 1/2
What is the solution to the equation below?
√2x/√x-1=2
A. 4 B. 2 C. 5 D.3
Answers
Given:
The given equation is:
[tex]\dfrac{\sqrt{2x}}{\sqrt{x-1}}=2[/tex]
To find:
The solution for the given equation.
Solution:
We have,
[tex]\dfrac{\sqrt{2x}}{\sqrt{x-1}}=2[/tex]
On simplification, we get
[tex]\sqrt{2x}=2\sqrt{x-1}[/tex]
Squaring both sides, we get
[tex]2x=4(x-1)[/tex]
[tex]2x=4x-4[/tex]
[tex]2x-4x=-4[/tex]
[tex]-2x=-4[/tex]
Divide both sides by -2.
[tex]x=\dfrac{-4}{-2}[/tex]
[tex]x=2[/tex]
Therefore, the correct option is B.
The path of a projectile launched from a 20-ft-tall tower is modeled by the equation y = -5x2 + 40x + 20. What is the maximum height, in meters
reached by the projectile?
Answers
Answer:
30.49 m
Step-by-step explanation:
To obtain the maximum height, we solve for the value x when dy/dx = 0.
Since, y = -5x² + 40x + 20
dy/dx = d[-5x² + 40x + 20]/dx
dy/dx = -10x + 40
Since dy/dx = 0,
-10x + 40 = 0
-10x = -40
x = -40/-10
x = 4
Substituting x = 4 into the equation for y, we have
y = -5x² + 40x + 20
y = -5(4)² + 40(4) + 20
y = -5(16) + 160 + 20
y = -80 + 160 + 20
y = 80 + 20
y = 100 ft
Since y is in feet, we convert to meters.
Since 1 m = 3.28 ft, 100 ft = 100 ft × 1 m/3.28 ft = 30.49 m
So, the maximum height, in meters reached by the projectile is 30.49 m
