Question

A triangle has side lengths of 5a+3 5 a + 3 inches and 2a+3 2 a + 3 inches. If the perimeter of the triangle is 9a+12 9 a + 12 inches, which expression represents the lengths, in inches, of the third side of the triangle?

Answer 1

The answer to your question is: side 3 = 2a + 6

Explanation:

Data

Triangle

side 1 = 5a + 3 inches

side 2 = 2a + 3 inches

side 3 = ?

Perimeter = 9a + 12

Process

Perimeter = side 1 + side 2 + side 3

9a + 12 = (5a + 3) + (2a + 3) + side 3

side 3 = 9a + 12 - 5a - 3 - 2a - 3

side 3 = 2a + 6