Question

A paper cup shaped like a cone has a diameter of 6 centimeters and a slant height of 7.5 centimeters. How much paper is needed to make the cup.

Answer 1

Answer:

22.5 cm^2

Step-by-step explanation:

Amount of paper is going to be measured in area, so we want the surface area of the cone.  Since it is a cub it doesn't have a base, so we don't need to count it.  

Area of the cone without the base, or what is called the lateral area is pi*r*s where r is the radius and s is the slant height.  and of course radius is d/2 where d is the diameter.  so let's plug it in.  We know diameter is 6 and slant height is 7.5

SA = pi * r * s

SA = pi * d/2 * s

SA = pi * 6/2 * 7.5

SA = 22.5 cm^2

So you will need 22.5 square centimeters of paper.