Aptitude - Volume and Surface Area - Discussion
Discussion Forum : Volume and Surface Area - General Questions (Q.No. 1)
1.
A right triangle with sides 3 cm, 4 cm and 5 cm is rotated the side of 3 cm to form a cone. The volume of the cone so formed is:
12
cm3
cm315 cm3
cm316 cm3
cm320 cm3
cm3Answer: Option
Explanation:
Clearly, we have r = 3 cm and h = 4 cm.
 Volume = |
1 | r2h = |
 |
1 | x x 32 x 4 |
 cm3 |
= 12 cm3. |
| 3 | 3 |
Video Explanation: https://youtu.be/Njsid2mVwUY
Discussion:
77 comments Page 7 of 8.
Shinu said:
9 years ago
Pi factor should be included.
Aashish said:
10 years ago
We can take 4 as base. And according to which volume will be 16*pi or remove 16*pi from the options.
Or we can have only one correct option either 12pi or 16pi.
Or we can have only one correct option either 12pi or 16pi.
Srikanth said:
10 years ago
Volume of cone is (1/3)*pi*r*r*h = (1/3)*(22/7)*3*3*4 then, the value will be 12(22/7)cm^3.
Suhail said:
10 years ago
Dear friend,
As it is moved along the side 3 cm hence this 3 cm will be distributed entire circumference.
So 3 = 2*22/7*r.
r = 3/2Π.
As it is moved along the side 3 cm hence this 3 cm will be distributed entire circumference.
So 3 = 2*22/7*r.
r = 3/2Π.
Tina said:
10 years ago
If 3 cm side is rotated, shouldn't it form circumference of cone?
Then 2*pie*r = 3.
How can r itself be 3 here?
Then 2*pie*r = 3.
How can r itself be 3 here?
V!CKY said:
10 years ago
@Sakshi and other who doubt in radius @ read question carefully.
i.e rotated the side of 3 cm to form a cone.
Diameter = 2*Radius.
i.e rotated the side of 3 cm to form a cone.
Diameter = 2*Radius.
Rama said:
10 years ago
Since triangle is rotated with side of 3 cm hence radius is 3.
Clearly, we have v-1/3*r*r*h.
Clearly, we have v-1/3*r*r*h.
Pankaj Dhariwal said:
10 years ago
I can't understand. In this question where we use 5cm. Please explain.
Sachin.nani3@gmail.com said:
1 decade ago
I could not understand, please explain any body.
Sravanthi said:
10 years ago
It is not mentioned that 3 is base and 4 is height. Why can't 3 be height and 4 be base? please explain.
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