Question

A homeowner wants several small dormers built on his roof to admit light. They will be in the shape of isosceles triangles whose sides will exceed their base by 5 in. If the perimeter is 100 in., what are the lengths of the three sides? The base is and the equal sides are .

Answer 1

P = s + (s + 5) + (s + 5) This represents the two sides that are 5 inches longer than the base (s + 5) and the base (s).
Simplifying.
100 = 3s + 10
subtract 10 from both sides
 90 = 3s
divide both sides by 3
30 = s
base = 30
sides = 35

CHECK 30 + 35 + 35 = 100