If the area of the base of a cone is 154 cm2 and the area of its curved surface is 550 cm2, then its volume is: |
1232 cm3 1122 cm3 1434 cm3 1535 cm3 |
1232 cm3 |
We know that, Volume of cone = \(\frac{1}{3}\)πr2h Curved surface area of cone = πrl Area of base of cone = πr2 We have, Area of base of cone = 154 cm2 Area of curved surface = 550 cm2 \(\frac{22}{7}\) × r2 = 154 = r2 = (154 × 7) × \(\frac{1}{22}\) = r2 = 49 = r = 7 cm Curved surface area of cone = 550 = \(\frac{22}{7}\) × 7 × l l =25 Now, h = \(\sqrt {l^2 – r^2}\) = h = \(\sqrt {25^2 – 7^2}\) = \(\sqrt {625 – 49}\) = h = 24 Volume of cone = \(\frac{1}{3}\) × \(\frac{22}{7}\) × 7 × 7 × 24 = 22 × 7 × 8 = 1232 cm3 |