What is the curved surface area of a cone if the base is 8cm diameter and the slant height is 10cm?
- 40pi
- 80pi
- 120pi
Explanation from PART66Online
The curved surface area of a cone is pi*r*l. The radius is half the 8 cm diameter, so r = 4 cm, and the slant height l = 10 cm, giving pi*4*10 = 40pi square cm. The 80pi distractor results from using the full diameter instead of the radius.
R
roshraj asked · 30 Jul 2013
the height mentioned here is slant height?
Community Comments (5)
P
PART66Online
30 Jul 2013
Hey.
Yes, slant height. I'll correct this question to avoid any misunderstandings in future.
Yes, slant height. I'll correct this question to avoid any misunderstandings in future.
R
r.skybinskyi
1 Dec 2013
Cone without base area is supposed to be calculated.
P
PART66Online
1 Dec 2013
Uhu, without base.
J
JD2016
4 Sep 2016
That's an ambiguous and poorly phrased question. If you inserted the word "curved" before surface area, it would sort it out.
P
PART66Online
4 Sep 2016
Hi JD2016.
Yes, you are right.
Yes, you are right.
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