Question

area of the base of a cone is 1386 CM square and its height is 28 cm find its curved surface area​

Answer 1

Answer:

2307.4

Step-by-step explanation:

find r using the area of circle so r =21

find slant height using the given h and the r we got so it will result in l =35.

use the formula pie*r*l formula and find csa

Answer 2

The curved surface area of the cone is 2310 cm².

Step-by-step explanation:

Given : Area of the base of a cone is 1386 cm square and its height is 28 cm.

To find : Its curved surface area​ ?

Solution :

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

Area of the base of a cone is 1386 cm square.

So, $1386=\frac{22}{7}\times r^2$

$r^2=\frac{1386\times 7}{22}$

$r^2=441$

$r=\sqrt{441}$

$r=21$

Radius is r=21 and height is h=28 cm

The slant height is

$l=\sqrt{r^2+h^2}$

$l=\sqrt{21^2+28^2}$

$l=\sqrt{441+784}$

$l=\sqrt{1225}$

$l=35\ cm$

The curved surface area is given by

$CSA=\pi rl$

$CSA=\frac{22}{7}\times 21\times 35$

$CSA=2310\ cm^2$

The curved surface area of the cone is 2310 cm².

#Learn more

The height of a cone is 16cm and its base radius is 12cm. Find the curved surface area and the total surface area of the cone?

https://brainly.in/question/7490763