Question

the height and slant height of a cone are 21 CM and 28 CM respectively. fine the volume of the cone? ​

Answer 1

Answer:

By Pythagoras theorem,

(slant height)² = (radius )² + ( height)²

⇒radius² = (28)² - (21)²

              = (28 +21) (28- 21)

              = 49 × 7

radius = 7√7 cm

now, volume = ( π r² h)/3

                    =((22/7)× 343× 21)/3

                    = 7546 cm³

∴ volume = 7546 cm³

Step-by-step explanation:

Answer 2

Answer:

7546 cm³

Step-by-step explanation:

formula = 1/3 × π R²H

r² = slant height ² - Height ²

R² = 28² - 21²

R² = 784 - 441

R² = 343

1/3 × π × 343 × 21

1/3 × 22/7 × 343 × 21

22/21 × 343 × 21

22 × 343

= 7546 cm³