What is the surface area when the radius is 4 feet and the height is 6 feet?

Answer 1

assuming you're asking about a cylinder here...for the curved exterior surface, calculcate the circumference (pi x diameter, or 2pi x radius) and then multiply by the height. if the answer also needs to include the ends of the cylinder, then add twice the area of an end or the twice quantity of pi x r squared.

circumference x height = rounded surface area of cylinder:

3.14(8') x 6' = 150.72 square feet

plus the cylinder ends; twice pi x square of radius = area of cylinder ends:

2[3.14(4' x 4')] = 100.48 square feet

so, the total surface area of a 6' high cylinder with a 4' radius = 251.2 square feet.