Good evening ,
Answer:
D.60
Step-by-step explanation:
Perimeter of the the square = 4(3x+3) = 12x + 12
perimeter of the pentagon = 5(x+8) = 5x + 40
the perimeters are equal means 12x + 12 = 5x + 40
12x + 12 = 5x + 40 ⇔ 7x = 28 ⇔ x = 4
x=4 ⇒ 4(3x+3) = 4×15 = 60
⇒5(x+8) = 5(4+8) = 60
:)
