Radius of a cylindrical container 1 ft high with surface area of 4pi ft squared. What’s the radius of the circular top and bottom?

Answer 1

2*pi*r*h + 2 *pi*r^2

4*pi = 2*pi*r*1 + 2*pi*r^2 <--- height is 1

4 * pi = 2 * pi * r + 2* pi*r^2

2 = r + r^2 <--- divides by 2*pi

r^2 + r - 2 = 0

(r + 2)(r-1) = 0

r+2 results in negative measures

r=1

radius us 1