Answer:
144°
Step-by-step explanation:
step 1
Find the measure of the central angle of the regular pentagon
Divide 360 degrees by 5 (the number of sides)

Let
c----> the center of the pentagon
we know that
m∠ECA=72°
m∠ACB=72°
therefore
m∠ECB=m∠ECA+m∠ACB
substitute the values
m∠ECB=72°+72°=144°
The measure of angle ECB is equal to the degrees that the pentagon rotate
Answer:
true
Step-by-step explanation:
please see the image I attached of my work
Add all of the interior angles to 1260. Then you simplify for x. After that you plug in what you found for X in the E expression.
I will tell you use a calculator and leave the answer there. Try the math see if you get it correct. If you don't tell me!
3/4 + 2/3 = 17/12
7/8 - 2/3 = 5/24
3/5 x 1/3 = 1/5
4/7 x 2/3 = 8/21