Question

four times the area of the curved surface of a cylinder is equal to 6 times the sum of the areas of its bases. if its height is 12 cm find its curved surface area ​

Answer 1

603.42

Explanation:

Curved Surface Area = 2πrh sq.cm

Area of the base = πr² sq. cm

Sum area of the base = πr² + πr² = 2πr² sq.cm

A.T.Q

4(2πrh) = 6x2πr²

8πrh = 12πr²

2h = 3r

r = 8 cm

Curved Surface Area = 2πrh

2x22/7x8x12

4224/7

603.42

Answer 2

Explanation:

Curved surface Area = 2πrh

Area of its bases = 2πr²

6* Area of its bases = 4 * Curved surface Area

6 * 2πr² = 4 *2πrh

r² / r = 4 * 2* π*12 / 6 * 2 * π { substituting h =12 cm}

r = 4*2

r = 8 cm

Curved surface Area = 2πrh

= 2 * 3.14 * 12 * 8

= 602.88 Sq. cm