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.
Sam singh said:
8 years ago
If we rotate the angle from side of 4 cm thn what will be perpendicular?
D Priya said:
8 years ago
A cone can be rotated and formed from a triangle by considering the base. Rotate the 4cm angle to the base and proceed.
Tanisha jha said:
7 years ago
I can't understand please help me to understand it.
Red Anca said:
7 years ago
I think the h=3 due to the problem rotated about 3cm..and the base or raduis will be r=4cm,
We can redirect to the formula;
V=1/3 * 3.141592654 * r'2 * h,
V=1/3 * 3.141592654 * 4'2 * 3.
V = 50.26 cm'3.
We can redirect to the formula;
V=1/3 * 3.141592654 * r'2 * h,
V=1/3 * 3.141592654 * 4'2 * 3.
V = 50.26 cm'3.
Shubhsm said:
7 years ago
How deside 3 cm are base?
Durga said:
7 years ago
Could you please explain it in clear?
Mohit kumar chaudhary said:
7 years ago
I am not getting the answer. Please explain to me.
(2)
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)
RAHUL robin said:
7 years ago
Incorrect/missing preposition in the question makes it confusing as one can't get whether the triangle is rotated with/about the side of 3 cm.
If it's rotated with the side of 3 cm then r=3, h=4. If it's rotated about the side of 3 cm then r=4, h=3.
If it's rotated with the side of 3 cm then r=3, h=4. If it's rotated about the side of 3 cm then r=4, h=3.
(2)
Shivam Ahuja said:
6 years ago
I think the answer may be 16π as per question, it does not tell us about along which axis we have to rotate it.
(1)
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