Answer :
Answer:
The longest length is 30 cm
Step-by-step explanation:
Mathematically, the perimeter of a triangle is simply the sum of the lengths of its three sides
So, what we have to do here is divide the perimeter in the given ratio to get the side lengths
since 5 is the biggest of the numbers in the ratio, it represents the largest length value
so we have this as;
(3 + 4 + 5) = 12
So that would be;
5/12 * 72
= 5 * 6 = 30