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What is the surface area of the cone?

Question

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What is the surface area of the cone?

mathstudent55 · Answer

$SA_{cone} = A_{lateral} + A_{base} $

$A_{lateral} = \pi r h_{slant} $

$A_{base} = \pi r^2 $

mathstudent55 · Answer

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anonymous · Answer

@Math81 i got 120 is that correct

mathstudent55 · Answer

$SA_{cone} = A_{lateral} + A_{base} $

$SA_{cone} = \pi r h_{slant} + \pi r^2 $

First we need the slant height.

mathstudent55 · Answer

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The slant height is 13 cm.

mathstudent55 · Answer

$SA_{cone} = \pi r h_{slant} + \pi r^2$

$SA_{cone} = \pi (5 ~cm)(13 ~cm) + \pi (5 ~cm)^2 $

$SA_{cone} = 65 \pi ~cm^2 + 25 \pi ~cm^2 $

$SA_{cone} = 90 \pi ~cm^2 \approx 282.74 ~cm^2$