Question

Find the total area of a cylinder whose radius is 2 cm and height is 4 cm

Answer 1

I assume it is asking for the surface area of a cylinder. A cylinder is composed of 2 parts. It has 2 circles and one rectangle. So lets solve for the circles:

The area is πr^2. Given our radius, 2, we can substitute into our r.
That gives us 4π. But since we have two circles, it is 8π

Next we solve for our rectangle. Our height is 4 and our base is 2πr or 4π
4 * 4π = 16π

Finally we add.

We get 16π + 8π = 24π ≈ 75.398 cm^2