Question

The triangle and square have equal perimeters. What is the perimeter of the triangle?

A. 18
B. 4
C. 12
D. 32
E. 16
F. 24

Answer 1

E. 16

Explanation:

Perimeter of the triangle = 4x+4x+(x+7)

Perimeter of square = 4(x+3)

We know that the perimeters are equal so we can form an equation to solve for x:

9x+7 = 4x + 12

Now we can subtract 4x from both sides to move the xs to the left side, and the same with the 7 so we have the variable on one side and the constant on the other:

9x+7-7-4x=12+4x-4x-7

5x = 5

Now we divide both sides by 5 to get:

5x/5 = 5/5

x = 1

Now we can use this value to figure out the perimeter of the triangle:

P = 9x + 7

x=1, substitute into equation:

P = 9(1) + 7

P = 16

Hope this helped!