CUET Preparation Today
A hemisphere has 42 cm diameter. Find its curved surface area and the total surface area. |
$2772cm^2 , 4158cm^2$ $3772cm^2 , 5158cm^2$ $4770cm^2 , 4238cm^2$ $3072cm^2 , 4058cm^2$ |
$2772cm^2 , 4158cm^2$ |
We know that, Curved surface area = 2πr2 The total surface area = 3πr2 Diameter of the hemisphere = 42 cm Radius of hemisphere = \(\frac{42}{2}\) = 21 cm CSA = 2π(21)2 = CSA = 2(\(\frac{22}{7}\))(441) = CSA = \(\frac{19404}{7}\) = 2772 cm2 Now , TSA = 3π(21)2 = TSA = 3(\(\frac{22}{7}\))(441) = \(\frac{29106}{7}\) = 4158 cm2 |
