A rectangular region with dimensions 7 cm and 10 cm is revolved around the 10 cm side. Find the total surface area of the obtained shape

Question

A rectangular region with dimensions 7 cm and 10 cm is revolved around the 10 cm side. Find the total surface area of the obtained shape

Answer 1

The shape is a cylinder with height 10 and radius 7. It's shaped like a can of soup.

Surface Area of a cylinder is two times the top area so as to include the bottom, that's 2 times the area of a circle plus the height times the circumference: 2pi(r)^2 + 2pirh

= 2pi(7)^2 + 2pi(7)(10)

=2pi[49+70]

=238pi

=238(3.14159)

=747.7 square cm.