Q:

The solid figure shown consists of a cylinder and a cone. The cylinder has a radius of 12 centimeters and a height of 20 centimeters. The total height of the solid is 25 centimeters. The slant height of the cone is 13 centimeters. Which choice is closest to the total surface area of the solid? Use 3.14 to approximate pi.

Accepted Solution

A:
ah yes the surface area questions:

Surface area for cylinder:
2πrh + πr^2 (because I'm guessing the cone is on top of the cylinder, so one of the bases doesn't count in the surface area)
= 2*3.14*12*20 + 3.14*(12^2)
= 1507.2 + 452.16
= 1959.36 cm^2

Surface area for cone (no base because it is connected to the cylinder)
1/2*2rπ*l = r*π*l = 12*3.14*13 = 489.84 cm^2

Total surface area = 1959.36+489.84 = 2449.2 cm^2

Not sure why you would need to total height of it if you already have the slant height tho, besides using it to find the height of the cone and the radius, IF YOU DON'T HAVE THE SOLID SHOWN AS A MODEL

but yea I found that they have the same radius so I guess it does make sense a bit, since you don't post the original picture of the solid.