1. ## Triangle problem

The lengths of the sides of a triangle are 3, 8, and 9 inches. How many inches long is the shortest side of a similar triangle that has perimeter of 60 inches?

Not sure why the answer is 9...??

2. Originally Posted by sarahh
The lengths of the sides of a triangle are 3, 8, and 9 inches. How many inches long is the shortest side of a similar triangle that has perimeter of 60 inches? Not sure why the answer is 9...??
You might note that 3+8+9=20 and 3(20)=60. So the ‘scale’ is 3.
If S, M, L stand for small, middle, and large the in the larger similar triangle we would have $\frac{S}{3} = \frac{M}{8} = \frac{L}{9}\,\& \,S + M + L = 60$.
Solving for S we get S=9.