Geometry

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Geometry

by talaangoshtari » Wed Jul 22, 2015 5:09 am
A sector of a circle of radius 5 cm is recast into a right circular cone of height 4 cm. What is the volume of the resulting cone?

A. 12Ï€ cm3
B. 100Ï€ cm3
C. 33Ï€ cm3
D. 32Ï€ cm3
E. 4Ï€ cm3

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by Jim@StratusPrep » Wed Jul 22, 2015 5:18 am
This is essentially saying that you are to calculate the volume of a cone with a radius of 5 and height 4.

1/3Ï€r^2h = = 1/3(100Ï€) = 33Ï€

However, not likely a phrasing you will see on the GMAT.
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by Brent@GMATPrepNow » Wed Jul 22, 2015 5:30 am
talaangoshtari wrote:A sector of a circle of radius 5 cm is recast into a right circular cone of height 4 cm. What is the volume of the resulting cone?

A. 12Ï€ cm3
B. 100Ï€ cm3
C. 33Ï€ cm3
D. 32Ï€ cm3
E. 4Ï€ cm3
On the GMAT, you don't need to know the formula for the volume of a cone.

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by [email protected] » Wed Jul 22, 2015 8:13 am
Hi talaangoshtari,

When it comes to geometric 'solids', you DO need to know the formulas for Volume and Surface area for rectangular solids, cubes (which are just a specific type of rectangular solid) and cylinders. You do NOT need to memorize anything involving spheres, cones or pyramids. In the rare situation in which you deal with one of those shapes, you'll be given the necessary formula(s) to work with.

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by nikhilgmat31 » Wed Jul 29, 2015 3:23 am
what recast means here.
Does it means volume of sector of sphere is casted to make a cone.

or I am think too much.