Volume hemispherical bowl integration? (1 Viewer)

[johnlad]

apparently the circle formula has to be used, i don't get how to do it and why the circle formula is used?

 

[HeroicPandas]

Draw x^2 + y^2 = a^2 (from -a <=y <= 0)

and

fill the bowl up with some juice of a/2 tall

and find volume

 

[Shadowless]