Question

here is the question cutiepie

Answer 1

Hlo Palak!!

Here is ur answer :

First read the question properly, then you get to know that what the question is.

The semi circular sheet of diameter 28 cm is bent into the cone.

And the volume of cone formed is asked.

Volume of cone
$\frac{1}{3} \pi {r}^{2} h$

So u have to know the value of r and h.

Radius is r

Vertical height is h.


By observing all this you get to know that,

Circumference of semi circle = Circumference of cone

Radius R of semi circular sheet = 28 / 2 = 14 cm

$2\pi r \: = \pi \times 14$

$r = \frac{\pi \times 14}{\pi \times 2}$

$r = 7 \: cm$


Slant height l of cone = Radius R of sheet

l = 14 cm

Now, we have Slant height and radius, so we can find vertical height.

By formula,

l² = r² + h²

(14)² = (7)² + h²

196 = 49 + h²

h² = 196 - 49

h² = 147


$h = \sqrt{147}$

$h = 12.124 \: \: cm$

________________

Volume of cone =
$\frac{1}{3} \times \frac{22}{7} \times 7 \times7 \times 12.124$


$\frac{1}{3} \times 22 \times \: 7 \: \times 12.124$

$= 622.365$

Capacity of cone = 622.365 cm³


HOPE IT HELPS YOU..

I think it will clear ur doubt..