An equilateral triangle has sides of length s. If each side is increased by 15 , represent the new perimeter in terms of s.

We know that an equilateral triangle has all sides equal.

Initial perimeter = s + s + s = s

Each side has been increases by then the new perimeter is:

(s+15) + (s+15) + (s+15) = 3s + 45

So the new perimeter = 3s + 45