Question

8. The square and equilateral triangle below have equal perimeters. Find the value of x. Then, calculate the perimeter of each shape. 78 - 8.1 10x - 13 x: 8 Perimeter: 9​

Answer 1

x=3.3

P = 60

Explanation:

The perimeter of the square is

P = 4s

= 4(7x-8.1)

=28x -32.4

The perimeter of the equilateral triangle is

P = 3s

= 3(10x-13)

=30x-39

The perimeters are equal

28x -32.4 = 30x-39

Subtract 28x from each side

28x-28x -32.4 = 30x-28x-39

-32.4 = 2x-39

Add 39 to each side

-32.4 +39 = 2x-39+39

6.6 = 2x

Divide by 2

6.6/2 = 2x/2

3.3 =x

The perimeter is

30x-39 = 30*3.3 -39 = 99-39 = 60