A cone is & formed from a circle of radius 10 cm
with a 90° sector removed. Find removed. Find the volume of the ( cone.
Answers
Answer:
When a sector of radius R=21 cm & aperture angle θ=90∘=π/2 is folded to form curved surface of a right circular cone then the area of curved surface of cone becomes equal to the area of sector
hence, the total surface area of cone including inside & outside curved surfaces formed by sector
=2(12θR2)
=2(12π2(21)2)
=12π(441)
=12×227×441
=693 cm2
Step-by-step explanation:
Hope it helps you
Answer:
Correct option is
A
21
704
21
Slant height of cone = radius of circle from which sector is cut
l=10cm
Area length of 144
0
sector = 2π×radius×
360
0
144
0
= 2π×10×
360
144
=8π
Circumference of the base of cone = arc length = 8π cm
∴ 2πr=8π⇒r=4cm
h=
l
2
−r
2
=
10
2
−4
2
=
100−16
=
84
=2
21
∴ Volume of cone =
3
1
πr
2
h=
3
1
×
7
22
×4×4×2
21
=
21
704
21
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