Question

*If curved surface area of cone is 165 cm² If diameter of base of cone is 10.5 cm then what is the slant height of cone?*

1️⃣ 5 cm
2️⃣ 6 cm
3️⃣ 20 cm
4️⃣ 10 cm​

Answer 1

Step-by-step explanation:

Given :- Diameter of the base of a cone = 10.5 cm

Radius (r) of a cone = 10.5/2

Let the Slant height of a cone be "l"

Curved surface area of a cone = πrl sq. unit

According to the question,

$\pi \: rl = 165$

$= > \: \frac{22}{7} \times \frac{10.5}{2} \times l = 165$

$= > \frac{22}{7} \times \frac{105}{20} \times l = 165$

$= > \frac{33}{2} \times l = 165$

$= > l = 165 \times \frac{2}{33}$

$= > l = 5 \times 2$

$= > l = 10$

Answer :- The Slant height of a cone is 10 cm.