Answer:

Step-by-step explanation:
A regular polygon is a shape with equal sides and angles. Because of this, we can write the following equation to set two sides equal to each other:

Solving, we will get a in terms of b:

Now we can substitute a for (b+3) into our equation:

Therefore, the length of each side of this polygon is
.
Since the perimeter of the polygon consists of all five sides, the perimeter is:

I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
SEE ATTACHED IMAGE.
Using Heron's Formula we can find the area of the triangle.
A = root (s (s-a) * (s-b) * (s-c))
s = (a + b + c) / 2
Where,
s: semi-perimeter
a, b, c: sides of the triangle
Substituting values:
s = (15 + 16 + 20) / 2
s = 25.5
s = 26
The area will be:
A = root (26 * (26-15) * (26-16) * (26-20))
A = 130.9961832
A = 130 u ^ 2
Answer:
The area of triangle ABC is:
C.
130 u ^ 2
4(2x-5)
8x-20
it is equal to 8x-20 because you simplify it and it turns into that.
HOPE I HELPED!!!
<span>9a + -3(2a + -4) = 15
Reorder the terms:
9a + -3(-4 + 2a) = 15
9a + (-4 * -3 + 2a * -3) = 15
9a + (12 + -6a) = 15
Reorder the terms:
12 + 9a + -6a = 15
Combine like terms: 9a + -6a = 3a
12 + 3a = 15
Solving
12 + 3a = 15
Solving for variable 'a'.
Move all terms containing a to the left, all other terms to the right.
Add '-12' to each side of the equation.
12 + -12 + 3a = 15 + -12
Combine like terms: 12 + -12 = 0
0 + 3a = 15 + -12
3a = 15 + -12
Combine like terms: 15 + -12 = 3
3a = 3
Divide each side by '3'.
a = 1
Simplifying
a = 1</span>