Hi, there-- THE PROBLEM: If the ratio of the side lengths of a triangle is 2:3:4 and the shortest side is 15 in. What is the perimeter? A SOLUTION: First we find each side lengths using the ratios of one side to another. Then we add together the side length to get the perimeter. Step 1: Define variables. Let x be the shortest side. Let y be the longest side. Let z b the third side. The shortest side is 15 inches, so x = 15. The ratio of shortest side to longest side is 2 to 4. Our ratio isSolve for y. The longest side is 30 inches. The ratio of the third side to the longest side is 3 to 4. Our ratio is Solve for z. The third side measures 22.5 inches. The perimeter is the sum of the side lengths, or x+y+z The perimeter is 67.5 inches. Hope this helps! Mrs. Figgy math.in.the.vortex@gmail.com