The answer is l = [tex]\frac{A - \frac{1}{2} \pi w^{2} }{2w}[/tex]
In order to find that, follow the order of operations. There will only be two steps needed.
A = [tex]\frac{1}{2} \pi w^{2} + 2lw[/tex] ----> Subtract the first term
A - [tex]\frac{1}{2} \pi w^{2}[/tex] = 2lw -----> Divide by 2w
l = [tex]\frac{A - \frac{1}{2} \pi w^{2} }{2w}[/tex]
