Find the solution of chapter surface areas and volumes of ncert class 10th ,give me the best solution of the exercise 13.5 question number 2 . Also find the easiest and best way to solve this tricky question .A right triangle whose sides are 3 cm and 4 cm (other than hypotenuse) is made to revolve about its hypotenuse. Find the volume and surface area of the double cone so formed. (Choose value of π as found appropriate)
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A right triangle whose sides are 3 cm and 4 cm (other than hypotenuse) is made to revolve about its hypotenuse. Find the volume and surface area of the double cone so formed. (Choose value of π as found appropriate) Q.2
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Draw the diagram as follows:
Let us consider the ABA
Here,
AS = 3 cm, AC = 4 cm
So, Hypotenuse BC = 5 cm
We have got 2 cones on the same base AA’ where the radius = DA or DA’
Now, AD/CA = AB/CB
By putting the value of CA, AB and CB we get,
AD = 2/5 cm
We also know,
DB/AB = AB/CB
So, DB = 9/5 cm
As, CD = BC-DB,
CD = 16/5 cm
Now, volume of double cone will be
Solving this we get,
V = 30.14 cm3
The surface area of the double cone will be
= 52.75 cm2