Solve the perimeter formula for an isosceles triangle, p=2a+b , for b.
To solve for b in the perimeter formula for an isosceles triangle, we can rearrange the formula as follows:
p = 2a + b
b = p - 2a
Therefore, the formula for b in terms of the perimeter p and side length a of the isosceles triangle is b = p - 2a.