Question

This isosceles triangle has two sides of equal length, a, that are longer than the length of the base, b. The perimeter of the triangle is 15.7 centimeters. The equation 2a + b = 15.7 models this information. If one of the longer sides is 6.3 centimeters, which equation can be used to find the length of the base? 6.3 + b = 15.7 12.6 + b = 15.7 2a + 6.3 = 15.7 2a + 12.6 = 15.7

Answer 1

The formula for determining the perimeter of a triangle is expressed as

Perimeter = a + b + c

Where a, b and c represent the length of each side of the triangle.

Since the longer sides, a are equal, then the expression for the perimeter is

2a + b = 15.7

Given that each of the longer sides, a is 6.3 centimeters, then the length of both sides is

6.3 * 2 = 12.6

Therefore, the equation that can be used to find the length of the base is

12.6 + b = 15.7