SOLUTION: a cone is made from a sector of a circle of radius 20cm and sectional angle of 120degrees. find the radius of the base of the cone

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Question 882902: a cone is made from a sector of a circle of radius 20cm and sectional angle of 120degrees. find the radius of the base of the cone
Answer by alicealc(293) About Me  (Show Source):
You can put this solution on YOUR website!
base circumference of the cone = arc length of the sector

Let:
r = radius of the base of the cone
d = diameter of the circle = 2*20 = 40 cm
pi%2A2%2Ar=%28120%2F360%29%2Api%2Ad
2%2Ar=%281%2F3%29%2A40
r=20%2F3
r = 20/3 cm = 6.67 cm

so, the radius of the base of the cone is 6.67 cm.