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

Return to Full Article

Coming soon

Add New Question

Question

What is the area of the base of a cone with a volume of 36 cubic inches and height of 9 inches?

Community Answer

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.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 5 Helpful 9
Question

How do I show that slant height is 2r?

Community Answer

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

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 5 Helpful 9
Question

How do I find the radius of the base of a cone given its surface area of 500 pi and height of 15 cm?

Donagan

Top Answerer

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.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 6 Helpful 6
Question

How do I find the radius of a cone?

Community Answer

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.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 13 Helpful 7
Question

How do I find the height of a cone if I am only given the surface area of 96 cm2?

Donagan

Top Answerer

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

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 3 Helpful 7
Question

How can I find the surface of a cone if I have just the slant height without the radius?

Donagan

Top Answerer

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

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 7 Helpful 6
Question

How would I find out the surface area given the slant height and the height?

SMN

Community Answer

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

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 1 Helpful 0
Question

How to find the surface area of a cone while having no radius or height?

Donagan

Top Answerer

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.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 0 Helpful 0
Question

How would you do the problem above but with the bottom of the cone as a cylinder?

Donagan

Top Answerer

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).

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 0 Helpful 0