Answer:
7.7u - 5.1v + 14.5w
Explanation:
Given length:
Side A = (1.2u+1.8v) centimeters,
Side B = (6.5u+8.7w) centimeters
Side C = (5.8w-6.9v) centimeters
Perimeter of a triangle = side A + side B + side C
= (1.2u+1.8v) + (6.5u+8.7w) + (5.8w-6.9v)
= 1.2u + 1.8v + 6.5u + 8.7w + 5.8w - 6.9v
Collect like terms
= 1.2u + 6.5u + 1.8v - 6.9v + 8.7w + 5.8w
= 7.7u - 5.1v + 14.5w
Therefore, the perimeter of the triangle is 7.7u - 5.1v + 14.5w