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 5 of 8.
Swati said:
1 decade ago
Anyone solve this last step of questions?
My answer is not coming 12. I think wrong answer.
My answer is not coming 12. I think wrong answer.
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.
Kaveri said:
7 years ago
It is;
r=3, h=4.
volume = 1/3 * 2 2/7 * r2 * h.
v = 1/3 * 22/7 * 9 * 4.
v = 12 * 22/7cm3.
r=3, h=4.
volume = 1/3 * 2 2/7 * r2 * h.
v = 1/3 * 22/7 * 9 * 4.
v = 12 * 22/7cm3.
(2)
Silky said:
1 decade ago
@Sakshi is right. If it is rotated about 3 cm then its radius should be 3/2 = 1.5 cm.
Gini said:
1 decade ago
I think 3 cm is the surface area of the circle at the base.
Then, 3 cm=22/7*r*r.
Then, 3 cm=22/7*r*r.
Shafi said:
1 decade ago
Since triangle is rotated with a side of 3 hence radius=3, volume=1/3*22/7r^2h.
Sam singh said:
8 years ago
If we rotate the angle from side of 4 cm thn what will be perpendicular?
Vidhya said:
1 decade ago
If the side of 3cm is rotated, won't it become the height of the cone ?
Pritam said:
1 decade ago
Why should the base be taken as 3? why can't it be 4? what's the logic?
Prabhu said:
1 decade ago
If it is rotated along the side with 3cm then how could radius be 3cm?
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