Answer:
(A - pi r^2)/ 2 pi r= h
Explanation:
A = pi r^2 + 2 pi rh
First subtract pi r^2 from each side
A - pi r^2= pi r^2 + 2 pi rh - pi r^2
A - pi r^2= 2 pi rh
Now divide each side by 2pi r
(A - pi r^2)/ 2 pi r= 2 pi rh / 2pi r
(A - pi r^2)/ 2 pi r= h