Question

A cylinder has a diameter of 6 cm and a height of 28 cm. What is the total area of the cylinder???

Answer 1

The answer is 565.2 cm sq. Note that we are finding the SURFACE AREA AND NOT THE VOLUME.

We are finding the surface area of the cylinder. A cylinder is basically a rolled up rectangle with two circles on the top and bottom.

First we will find the area of the rectangle. It has a height of 28. The width is the same as the diameter of the circumference of the circle. This gives us 18.84. This means the rectangle has an area of 527.52.

Now we need to find the area of the circles. While looking for the rectangle, we saw the area for one was 18.84. The circles are congruent, so we double it, giving us 37.68.

Now we add the rectangle and the circles, giving us 565.2 as the surface area.

Answer 2

If we count only the area of the outside of the cyl., it is

A = Circumference times Height, or A = (6 cm)*pi*(28 cm)

Please complete the arithmetic to find the final answer.