Question

A triangle has a perimeter of 160cm. Side A is 5cm shorter than twice side B, and side C is 5cm longer than side B. Find the length of each side.

Answer 1

B = x

A = 2x - 5

C = x + 5

The perimeter P = A + B + C and P = 160 cm

Substitute

(2x - 5) + x + (x + 5) = 160

(2x + x + x) + (-5 + 5) = 160

4x = 160 |:4

x = 40 cm

A = 2x - 5 → A = 2(40) - 5 = 75 cm

B = x → B = 40 cm

C = x + 5 → C = 40 + 5 = 45 cm