To find the surface area first we have to find the height and radius we already have the height but we don't have the radius. To find the radius we use the diameter and divide it by 2. The diameter in the picture is 9. 9/2=4.5 so the radius is 4.5. Then we have to use the surface area formula for the surface area of a cone A=πr(r+h2+r2)
