Q&A for How to Find the Surface Area of Cones

The formula for volume of a cone is 1/3 x Base Area (i.e. area of a circle) x height. Solution: Volume = 1/3 x BA x H 36 = 1/3 x (BA)* x 9 36 x 3 = BA x 9 (we moved the 1/3 to the other side of the equation, hence it reciprocated) 108/9 = BA Base area of the cone is 12 inches.

If you're given the radius of the base and the height of the cone, you can do the Pythagorean theorem.

Assuming you are given the lateral surface area and the slant height, divide the lateral surface area by the product of pi and the slant height. If instead of the slant height you are given the perpendicular height, use Method 2 above to find the slant height, then multiply the slant height by pi, and divide that product into the lateral surface area to get the radius of the base.

The question will either give you the radius or the diameter. If it gives you the diameter, divide the diameter by 2 to get the radius.

You can't do it. You would also have to know the radius.

As explained above, if you know the slant height, you also need to know the radius to find the surface area.

You would do SA=SH. Where SA equals surface area, S equals slant height and H equals height.

As the above article explains, you need the radius and either the height or the slant height of the cone. Without them, you can't find the surface area.

To find the surface area of a cylinder with a cone of the same diameter sitting on its top, you would have to know the radius of the cone (and the cylinder), the height of the cylinder and the height or slant height of the cone. Then you would add together the lateral surface area of the cylinder (but not its base area) (see Find the Surface Area of Cylinders plus the lateral area of the cone (but not its base area).