SURFACE AREA FORMULA, SOLVE FOR RADIUS, R

Question

2πrh+2πr^2

Answer 1

A=2∏rh+2∏r²

subtract A from both sides

2∏r²+2∏rh-A=0

use the quadratic formula...

a=2∏, b=2∏h, c=-A

(-2∏h±√([2∏h]²-4(2∏)(-A))/2(2∏)

you can finish it up from here...