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A cone has a volume of 423pi cm^3 and height of 9cm. Calculate the surface area of the cone.

User Ruy Rocha
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1 Answer

7 votes

Answer:

1328.43cm³

Explanation:

The equation for the volume is V=(πr²h)÷3

The equation for the surface area is SA=πr²+πrl

First solve for the radius using the volume:

423πcm³=πr²+πr×9

After solving this, the 2 possible x values will be -25.55 and 16.55

Since you can't have a negative surface area, the only option will be 16.55

Now your radius is 16.55 and the slant height is 9

π(16.55)²+π(16.55)×9

The surface area will be 1328.43cm³

User Endline
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4.5k points