Question

Find the surface area of the frustum. Show all work.
Pic: http://tinypic.com/r/34q31g9/7

Answer 1

The surface area not including the circles is:\[\pi (R+r)s=\pi (6+3)7=63 \pi \]Adding the area of the circles to the above gives a total suface area of:\[\pi (R+r)s+\pi R{}^{\wedge}2+\pi r{}^{\wedge}2=\pi (6+3)7+\pi 6{}^{\wedge}2+\pi 3{}^{\wedge}2=108 \pi \] http://mathworld.wolfram.com/ConicalFrustum.html