Answer:
It's C
Step-by-step explanation:
Answer:
5.
x + 2(x + 1) = 8 --> x = 2
y = 2 + 1 = 3
7.
3(9 + 2y) + 5y = 20 --> y = -7/11
x = 9 + 2(-7/11) = 85/11
9.
3(-1 - 2y) + 5y = -1 --> y = -2
x = -1 - 2(-2) = 3
If a pentagon is regular, then all of the sides are the same length. This means that

So, if
, the lengths of the sides evaluate to

So, all the sides of the pentagon are 21 units long, and AB is 21 units long as well, because all sides are the same length.
The person who explained the answer because you can see how they got the answer or the evidence they used to get the answer