Camille knew that a triangle had one side with a length of 16 inches and another side with a length of 20 inches. She did not know the length of the third side, but she did know that the perimeter was five times the length of the unknown side. How long is the unknown side?
In this case, the unknown side of the triangle has a length of 10 inches. This can be determined by using the formula for the perimeter of a triangle: P = a + b + c, where a and b are the lengths of the known sides and c is the unknown side. We can rearrange this equation to solve for c: c = P - a - b. In this case, P = 5c, so 5c - a - b = c, and c = 5c - a - b. Substituting the given lengths for a and b, we have 5c - 16 - 20 = c, and c = 10. Therefore, the length of the unknown side of the triangle is 10 inches.