Question

What is the surface area of a cylinder with a diameter of 8 centimeters and a height of 12 centimeters?

Answer 1

The formula for this is $A=2 \pi rh+2 \pi r^{2}$.  If the diameter is 8 the radius is 4, so filling in accordingly we have $A=2 \pi (4)(12)+2 \pi (16)$ and $A=96 \pi +32 \pi$ which is $A=128 \pi$ and when you multiply in 3.14 you get that A = 401.92 or B above.