Question

The height and radius of a right circular cone are 24 cm and 7 cm respectively. The slant height of the cone is:

• A. 24 cm
• B. 31 cm
• C. 26 cm
• D. 25 cm

Answer 1

Answer: (D)

25 cm

Answer 2

The slant height $l$ of a right circular cone can be calculated using the Pythagoras theorem, as it forms a right triangle with the height and radius:

$l = \sqrt{r^2 + h^2}$

Substitute the given values $r = 7 \, \text{cm}$ and $h = 24 \, \text{cm}$:

$l = \sqrt{7^2 + 24^2} = \sqrt{49 + 576} = \sqrt{625} = 25 \, \text{cm}$

Thus, the slant height is 25 cm.