algebra
posted by Laura .
The sides of a triangle are in the ratio 5:12:13. What is the length of each side of the triangle if the perimeter of the triangle is 15 in?

Let a side have ratio value 5.
Let b side have ratio value 12.
Let c side have ratio value 13.
add the ratios of the sides:
5 + 12 + 13 = T
It is given that the perimeter (all sides added) is 15 inches. The length of each side has the same relationship to its ratio as the perimeter does to the ratio total.
a/5 = 15/T
b/12 = 15/T
c/13 = 15/T