Answer:
the answee is 3
Step-by-step explanation:
4a + 3 - 9 = -7 + 2 + a
4a - 6 = -5 + a
4a - a = -5 + 6
3a = 1 / : 3
a = 1/3
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.
A and 0 both equals 45 degrees
Answer:
Option 3
Step-by-step explanation:
This is the same reason that Pythagorean's Theorem works. The area made up of the X and Y Regions (the squares of the two legs of the triangle) is equal to Region Z (the square of the hypotenuse)