Question

2. If the diameter of a cylinder
is 28 cm and its height is 20 cm,
then its curved surface area is​

Answer 1

Radius = 28/2= 14

Height = 20

CSA of cylinder = 2πrh

= 2* 22/7* 14* 20

= 44* 2* 20

= 1760 sq. cm

(* is multiplication)

HOPE IT HELPS❤.

Answer 2

Diagram :-

$\setlength{\unitlength}{1mm}\begin{picture}(5,5)\thicklines\multiput(-0.5,-1)(26,0){2}{\line(0,1){40}}\multiput(12.5,-1)(0,3.2){13}{\line(0,1){1.6}}\multiput(12.5,-1)(0,40){2}{\multiput(0,0)(2,0){7}{\line(1,0){1}}}\multiput(0,0)(0,40){2}{\qbezier(1,0)(12,3)(24,0)\qbezier(1,0)(-2,-1)(1,-2)\qbezier(24,0)(27,-1)(24,-2)\qbezier(1,-2)(12,-5)(24,-2)}\multiput(18,2)(0,32){2}{\sf{r}}\put(9,17.5){\sf{h}}\end{picture}$

$\huge \sf \: given$

• Diameter of cylinder - 28 cm
• Height of cylinder - 20 cm

$\huge \sf \: to \: find$

CSA of cylinder

$\huge \sf \: solution$

So, first we have to find the radius from diameter

As we know that

$r \: = \frac{ diameter}{2}$

$r \: = \frac{28}{2}$

$r = 14$

Now

Radius is 14

Finding CSA of cylinder

$\huge \bf{csa \: \: = 2 \: \pi \: rh}$

$csa \: = 2 \times \frac{22}{7} \times 14 \times 20$

$csa \: = 11 \times 2 \times 20$

$csa \: = 440$