why is total surface area of a hemisphere taken 3Ï r2 - Maths - Surface Areas and Volumes

Question

why is total surface area of a hemisphere taken 3Ï€r 2

Mayank Bhardwaj · Accepted Answer

On cutting a sphere into two halves i e ,hemispheres, the curved surface is divided into two parts Also, it can be seen that a flat circular base appears on the hemisphere âˆ´ Total surface area of hemisphere $= \frac{1}{2}$ (curved surface area of sphere) + Circular base area

$= \frac{1}{2} (4 π r^{2}) + π r^{2} = 2 π r^{2} + π r^{2} = 3 π r^{2}$

why is total surface area of a hemisphere taken 3πr 2

why is total surface area of a hemisphere taken 3πr ²