Question

6. Find the area of base and radius of a cylinder if its curved surface area is 990 sq cm and height is 15 cm.​

Answer 1

Given:-

• Curved surface area = 990 cm²
• Height = 15 cm

To Find:-

• Area of base
• Radius

Formula used:-

• CSA of Cylinder = 2πrh
• Area of circle = πr²

Solution:-

➨ CSA = 2πrh

➨ 990 = 2 × 3.14 × r × 15

➨ 990 = 94.2 × r

➨ r = 10.5095...

➨r = 10.5 cm

Now, Finding the area of base:-

➨ Area of base = πr²

➨ Area of base = 3.14 × (10.5)²

➨ Area of base = 346.185 cm²

Hence, the radius of the cylinder is 10.5 cm and the area of base is 346.185 cm².

━━━━━━━━━━━━━━━━━━ $\:$

Answer 2

Solution:-

$:\implies$ CSA = 2πrh

$:\implies$ 990 = 2 × 3.14 × r × 15

$:\implies$ 990 = 94.2 × r

$:\implies$ r = 10.5 cm

Now,

$:\implies$ Area of base = πr²

$:\implies$ Area of base = 3.14 × (10.5)²

$:\implies$ Area of base = 346.185 cm²

@${{\underline{\blue{theanuragkumar}}}}$_