Question
The area of the base of a right circular cone is 81π
cm² and its height is 12 cm. What is the curved surface area (in cm2) of the cone?Solution
The area of the base of a right circular cone is 81π cm πr2 = 81π ⇒ r2 = 81 ⇒ r = 9 The height of the cone is 12 cm The slant height of the cone (l) is AC = √ (92 + 122) ⇒ AC = 15 The curved surface area of the cone is π × 9 × 15 ⇒ 135π ∴ The curved surface area of the cone is 135π cm2
What value should come in place of (?) question mark in the given expression.
17 × 15 − 96 ÷ 8 + 6² = ?
Evaluate: 144 ÷ 12 × 6 + 35 − 4²
What will come in the place of question mark (?) in the given expression?
21 × 18 + ? – 19 × 15 = 25 × 24
2916 ÷ 54 = ? + 27
√324 + √484 + 63 = ?2Â
What will come in the place of question mark (?) in the given expression?
{(2/15) + (12/25)} of 375 + 190 = ?% of 375
- What will come in place of the question mark (?) in the following questions?
100−[20+4×5]=? (72 × 52 + 1555 )/(79+60) = 2000 ÷ ?
72 × 2 = ? + 104 – 14
672 ÷ 28 × 24 + 363 – 309 =?
