Question

The sector of
circle of radius 15cm has
the angle 120° . It is rolled
up so that two bonding
radii are joined together to from a cone. Find
the volume of
cone

​

Answer 1

Answer:

Given Radius of the circle = Slant height of the cone = 15cm.

Given Angle theta = 120.

We know that Length of the arc = theta/360 * 2pir

= 120/360 * 2pi * 15

= 2pi * 5

= 10pi.

Therefore the circumference = 10pi.

We know that Circumference of the base of cone = 2pir.

2pir = 10pi

2r = 10

r = 5cm.

We know that height of the cone h^2 = l^2 - r^2

= 15^2 - 5^2

= 225 - 25

= 200

h = 10 \sqrt{2} cmh=10

2

cm

Now,

Volume of the cone = 1/3pir^2h

= \frac{1}{3} * \frac{22}{7} * (5)^2 * 10 \sqrt{2}=

3

1

∗

7

22

∗(5)

2

∗10

2

= \frac{22 * 25 * 10 * 1.414}{3 * 7 3∗7

22∗25∗10∗1.414

= \frac{7777}{21}=

21

7777

= 370.33cm^3.=370.33cm

3

.

Hope this helps!

......................................................

MARK ME AS BRAINLIEST ANSWER

FOLLOW ME

LIKE MY ANSWER