A sector with a radius of 30 cm and a central angle of 120 ° is used to form the side of a cone. What is the total area of the cone

Bus = 30 cm
Radius = 30 △ 360 ° 120 ° = 10 cm
Full area
=Bottom area + side area
=3.14×10²+3.14×10×30
=1256 square centimeters

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