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Mathematics 23 Online
OpenStudy (traylea):

I always medal. Find the surface area of a cone. (screenshot of the cone here) http://prntscr.com/a70agj

OpenStudy (nikki_skellington):

468.23 or 468

OpenStudy (welshfella):

surface area = pi r^2 + pi r l where r = radius of the base and l = slant height

OpenStudy (traylea):

Um...ok. Can I have an explanation ?

OpenStudy (welshfella):

r = radius of the base . radius = 1/2 * diameter which you are given ( = 8) l = slant height of the cone = 7 Just plug these values in to the formula use 3.14 for pi

OpenStudy (traylea):

.5*4*7?

OpenStudy (welshfella):

no plug the values into pi r^2 + pi r l

OpenStudy (welshfella):

r = 1/2 * 8 = 4

OpenStudy (welshfella):

just replace pi by 3.14 , r by 4 and l by 7 and work it out. Use your caclulator.

OpenStudy (traylea):

ok.....

zepdrix (zepdrix):

|dw:1456252061967:dw|The pi*r^2 portion is what gives you the area of the circular bottom panel.

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