College Math Question

Question

A can of beans has surface area of 32 cm squared. Its height is 11 cm. What is the radius of the circular​ top?

Answer 1

If H = height of can = 11 cm, R = radius of the can

Then the surface area SA = 2*pi*R*H + 2*pi*R² = 32

Then SA = 22*pi*R + 2*pi*R² = 32

Rearranging and dividing by 2: pi*R² + 11*pi*R - 36 = 0

Solving for R using the quadratic equation we find that R = .445 cm