Question

A triangle has sides measuring 10, 14, and 18. A similar triangle has its largest side measuring 54. What is the perimeter of the similar triangle?

Answer 1

It was clearly stated that the two triangles are similar figures. Therefore, the ratio between the corresponding legs is the same.
Getting the ratio of two largest sides is below:
R=54/18
R=3
Solving the next missing side (let "b" represent the second missing side) using the value of R.
R=b/14, 3=b/14 and therefore b is equal to 42.
Solving the next missing side (let "a" represent the second missing side) using the value of R.
R=a/10, 3=b/10 and therefore b is equal to 30.
We have the three sides of the second triangle. Then we can solve for the perimeter using formula P=a+b+c.The solution is P=54+42+30 and answer is 126.