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A quarter sphere with a radius of $10 \text{ units}$.
Please help, also remember the sides.
I used the normal formula of the total surface area of a sphere and divided it by $4$, then added half the area of a circle but it wasn't equal to the correct answer.

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    $\begingroup$ try adding $\frac 34$ area of a circle $\endgroup$
    – Ant
    Commented Sep 29, 2014 at 15:16
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    $\begingroup$ You forgot the bottom side, so you need three quarters of a circle, not two. $\endgroup$
    – snar
    Commented Sep 29, 2014 at 15:28
  • $\begingroup$ So 1/4(4(PI)(10)^2) + 3/4( (PI)(10)^2 ) ? $\endgroup$
    – Brandon B
    Commented Sep 29, 2014 at 15:32
  • $\begingroup$ When I tried it like edited below, the answer matched $\endgroup$
    – Brandon B
    Commented Sep 29, 2014 at 17:56

1 Answer 1

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Let's first try to imagine the quarter of the solid sphere:

semihemisphere

It has a curved surface and $2$ mutually perpendicular plane surfaces

$$\text{T.S.A} = \underbrace{\frac{1}{4} 4\pi r^2}_{\text{curved surface area}} + \overbrace{\frac{1}{2}\pi r^2 + \frac{1}{2}\pi r^2}^{\text{Plane surface surface}} = 2\pi r^2$$

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  • $\begingroup$ What did you use to make the diagram? $\endgroup$
    – LarsH
    Commented Mar 14, 2015 at 19:32
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    $\begingroup$ @LarsH: Google Images... lol $\endgroup$
    – Nick
    Commented Mar 16, 2015 at 18:28

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