Question

Find the area of base and radius of a cylinder if its curved surface area is 660 sqcm
and height is 21 cm
​

Answer 1

$\huge\mathfrak\red{HELLO}$

The curved surface area of a cylinder is 2πrh

Area of the base of the cylinder is πr²

CSA is given as 660 cm and height is 21cm

660 = 2 × π × r × 21

660 = 2 × 22× r × 3

660= 132r

r = 660÷132

$\fbox{r=5cm}$

Area of the base of the cylinder is

Π × 5 × 5

22/7 × 5 × 5

550/7

=78.6 cm²

Answer 2

The radius is 5 cm.

The area of the base is 78.57 cm².

Step-by-step explanation:

Given : A cylinder if its curved surface area is 660 sq cm . and height is 21 cm .

To find : The area of base and radius ?

Solution :

The curved surface area of cylinder is

$CSA=2\pi r h$

Where, CSA= 660 sq cm  and h=21 cm

$660=2\times \frac{22}{7}\times r \times 21$

$r=\frac{660\times 7}{2\times 22\times 21}$

$r=5$

The radius is 5 cm.

The area of base of the cylinder is $A=\pi r ^2$

$A= \frac{22}{7}\times 5^2$

$A=78.57\ cm^2$

The area of the base is 78.57 cm².

#Learn more

The curved surface area of a cylinder is 1000cm and the radius of its base is 21 cm find the total surface area of the cylinder

https://brainly.in/question/7997122