Solve for h. rs + h^2 = l

[math_celebrity]

Solve for h. rs + h^2 = l

Subtract rs from each side to isolate h:
rs - rs + h^2 = l - rs

Cancel the rs terms on the left side, and we get:
h^2 = l - rs

Take the square root of each side:
h = sqrt(l - rs)