Question

A joker's cap is in the form of a right circular cone circumference 44 cm and slant height is 35 cm. What is the area of the sheet required to make 5 caps?
1. 3850 cm²
2. 4569 cm²
3. 1280 cm²
4. 4792 cm²

Answer 1

Correct Answer - Option 1 : 3850 cm²

Given:

Circumference of base of cap = 44 cm

Slant height of cap = 35 cm 

Formula Used:

Curved surface area = πrl

Circumference of circle = 2πr

Calculation:

Circumference of the base of cap = Circumference of circle = 2πr

⇒ 44 = 2πr

⇒ r = 7 cm

Curved surface area = πrl

⇒ Curved surface area = 22/7 × 7 ×  35

⇒ Curved surface area = 770 cm²

Sheet required to make 1 cap = 770 cm²

⇒ Sheet required to make 5 caps = 770 × 5 = 3850 cm²

∴ 3850 cm² sheet would be required to make 5 caps.

The correct option is 1 i.e. 3850 cm2