Question

Find the surface area of the cylinderGive your answer in terms of pi

Answer 1

We can find the area of the circles on top and bottom using pi*r^2

pi*1^2 = pi.. we have two circles so the total area is 2pi

For the remainder of the cylinder, let's flatten the tube into a rectangle. Imagine cutting a toilet paper roll and laying it flat. The height is given as 9, and the width is the circumference of the circle. C=2pi*r

So the area of the rectangle is 9*2pi*1 = 18pi

Add the 18pi and 2 pi for a total surface area of 20pi.