I need help with this geometry question. I will fan and medal.

Question

unofficialllyy · Answer

The main tank has a radius of 70 feet. What is the volume of the quarter-sphere sized tank? Round your answer to the nearest whole number. You must explain your answer using words, and you must show all work and calculations to receive credit.

unofficialllyy · Answer

I know that I have to use the formula for volume of a sphere, and then once I get the volume I multiply it by 4, right?

So I have written down: $$V=\frac{ 4 }{ 3 } \Pi r^3$$


Then I plug in 70 for r: $$V=\frac{ 4 }{ 3 } \Pi(70)^3$$

Is this correct so far?

unofficialllyy · Answer

@welshfella could you see if you could help? :)

unofficialllyy · Answer

@Loser66 ?

loser66 · Answer

why multiple by 4? the quarter sphere is 1/4 of the sphere. Not 4x Volume of the sphere.

unofficialllyy · Answer

Or divide by 4? I dont know

loser66 · Answer

$\div 4$

unofficialllyy · Answer

But am I right so far with what I have? After I got $$V=\frac{ 3 }{ 4} \Pi (70)^3$$
 I don't know how to solve this.

loser66 · Answer

ha!! |dw:1437249945106:dw|