Surface Area of a combination of solids
When we come across a combination of solids the problem of finding the material required to build such a solid arises. To find the surface area of such an solid we break into smaller solids and then find the curved surface area of each solid and add all areas to get the surface area of such an solid
e.g. In the given figure
Total surface area of the solid = Curved Surface Area of hemisphere + Curved Surface Area of cylinder
e.g. In the given figure
Total surface area of the solid = Curved Surface Area of cylinder + Curved Surface Area of cone
Let us see some examples to find surface area of combination of solids.
Example 1. The decorative block is made up of two solids-a cube and a hemisphere. The base of the block is a cube with edge 5 cm ,and the hemisphere fixed on the top has a diameter of 4.2 cm. Find the total surface area of the block.
Example 2. Mayank made a bird-bath for his garden in the shape of a cylinder with a hemispherical depression at one end. The height of the cylinder is 1.45 m and its radius is 30 cm. Find the total surface area of the bird-bath.