The base of an isosceles triangle is 12 in less than the len

The base of an isosceles triangle is 12 in. less than the length of the equal sides. If the perimeter of the triangle is 39 in., find the length of each of the sides.

Solution

Let x = the length of each of the two equal sides The base is 12 inches less or x-12 /\\ / \\ x/ \\x / \\ /________\\ x-12 left side + right side + base = perimeter x + x + x-12 = 39 3x - 12 = 39 3x = 51 x = 17 The two equal sides are 17 inches each The base is x-12 or 17-12 or 5 inches.