How do you find the area of each cylinder to the nearest whole number?

Answer 1

The Area of a rectangle is LxW . The area of a circle is PI x RxR where R is the radius of the circle. The Circumference or distance around a circle is 2xPIxR. To find the surface area of a cylinder with radius R (the radius of the circles at the top and bottom) and Length L(how tall the cylinder is) you first find the area of the circles on the bottom and top - then add it to the area of the tube part. If you unwrap the tube, it becomes a rectangle with the width 2xPIxR (since it was wrapped around the circles on top and bottom), and the Length L( how tall it is) . So it will be 2 circles plus the rectangle.

2 (PIxRxR) + 2xPIxRxL. Then round it to the nearest whole number. If the number on the right side of the decimal point is 5 or more, round up to the next whole number otherwise leave it the same. Then drop the numbers on the right side of the decimal point.