Find the surface area of a cone with a radius of 8in. and a height of 7 in.
I forgot the formula how to work this out can somebody help me. Thanks
Google can be a student's best friend. <g>
http://www.google.com/#q=surface+area+of+a+cone
SA = Lateral Area + Base Area
SA= (pi X radius X slant height) + (pi X r^2)
To find the slant height, use the Pythagorean Theorem.
Let me know if you need more help, it is no trouble at all :)
so the answer is 467.232 ???
A=πr(r+(√h^2+r^2))
Square root line continues at the top of h^2 through r^2. r is radius and h is height for this problem.
Now substitute numbers for the variables.
A=π8(8+(√7^2+8^2))
Now solve.
The rest I will leave up to you.
I hope this helps! :)
I still don't understand how to right it down to show my work. Please right it out for me thanks.
The part in the division is what's confusing me,.
This is what I get.
3.14*8(8+√49+64
25.12(8+√113
25.12+14.125
=39.245
I know I'm wrong
Callie, you don't need division I believe.
Multiply pi by the radius and that by the slant height. That counts as the lateral area. Then multiply pi by the radius-squared. Add those together.
Remember the slant height is not the same as the height, so use the Pythagorean Theorem to get this. :)
Hope this helps :)
What is the slant height? Or that them your talking about? Can't you just tell me the slant height?
The slant height would be 10.63014581, or rounded to 10.6 or even 11. Sorry, I thought you knew about the Pythagorean Theorem (a^2 + b^2 = c^2). :(
Anyways, hope this helps ;)