Math, asked by kumaraman7978, 4 months ago

the diameter of the base of a right circular cone is 21 cm and it's Hight is 14 cm . it's curved surface area is​

Answers

Answered by Anonymous
42

Answer:

Given :-

  • The diameter of the base of a right circular cone is 21 cm and it's height is 14 cm.

To Find :-

  • What is the curved surface area.

Formula Used :-

Pythagoras Theorem :

(Slant Height)²=(Radius)² + (Height)²

Curved Surface Area :

Curved Surface Area = πrl

where,

  • r = Radius
  • l = Slant Height

Solution :-

First, we have to find radius,

We know that,

Radius = Diameter/2

Then,

Radius = 21/2

Radius = 10.5 cm

Again, we have to find the slant height,

Given :

  • Radius = 10.5 cm
  • Height = 14 cm

According to the question by using the formula we get,

(l)² = (10.5)² + (14)²

(l)² = 110.25 + 196

(l)² = 306.25

l = √306.25

l = 17.5

Hence, the slant height is 17.5 cm

Now, we have to find the curved surface area of a cone,

Given :

  • Radius = 10.5 cm
  • Slant Height = 17.5 cm

According to the question by using the formula we get,

C.S.A of cone = 22/7 × 10.5 × 17.5

C.S.A of cone = 22/7 × 183.75

C.S.A of cone = 577.5 cm²

The curved surface area of cone is 577.5 cm² .


mddilshad11ab: Perfect explaination ✔️
Answered by TheBrainliestUser
14

Answer:

Its curved surface area = 577.5 cm²

Step-by-step explanation:

Given that:

  • The diameter of the base of a right circular cone is 21 cm then Radius = 21/2 = 10.5 cm
  • And its height is 14 cm

To find:

  • Its curved surface area.

Formula used:

Curved surface of right circular cone = πr√(r² + h²) sq. unit

Finding the curved surface area:

Curved surface area = π × 10.5 × √(10.5² + 14²) cm²

Curved surface area = π × 10.5 × √(110.25 + 196) cm²

Curved surface area = π × 10.5 × √(306.25) cm²

Curved surface area = π × 10.5 × 17.5 cm²

Curved surface area = (22 × 10.5 × 17.5)/7 cm²

Curved surface area = 577.5 cm²

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