Question

The first side of a triangle is 6 inches less than 4 times the second side. The third side of the triangle is six inches more than twice the second side. If the perimeter of the triangle is 60 inches, what are the lengths of its sides?

Answer 1

Let x inches the length of the second side of the triangle.

∴ Length of first side of triangle

= (4x - 6) inches

∴ Length of third side of triangle

= (2x + 6) inches

Perimeter of the triangle = 60 inches

∴ x + 4x - 6 + 2x + 6 = 60

7x = 60

∴ x = 60/7

∴ Length of first side of triangle

= (4x - 6) inches

= [4(60/7) - 6] inches

= 198/7 inches

= 28.3 inches (to 3sf)

∴ Length of second side of triangle

= x inches

= 60/7 inches

= 8.57 inches (to 3sf)

∴ Length of third side of triangle

= (2x + 6) inches

= [2(60/7) + 6] inches

= 162/7 inches

= 23.1 inches (to 3sf)