You must know that a hemisphere is a half of a sphere. Below are the formulas to find the curved surface area of a hemisphere (without the base circle area) and the total surface area of a hemisphere (with the base circle area).
Curved Surface Area of Hemisphere:
You must know that the surface area of a sphere is 4πr². A hemisphere is half of a sphere, this must mean that the curved surface area of a hemisphere is 2 divide by the surface area of a sphere. That is; 4πr²/2 which gives the following expression.
Total Surface Area of Hemisphere
If you’re to take into consideration the base circle below the curve meaning the total surface area. The surface area would be a combination of the above area and the area of the circle. As simple as that!. The area of the circle is πr². This means the total surface area is 2πr² + πr². If we simplify this gives 3πr² as expressed below.
Remember there is a difference between the curved surface area and the total surface area. The total surface area includes the base circle below the hemisphere and the curve surface area does not, it’s just the curve of the hemisphere.