Find the curved surface area of a cone of radius 21 cm and height 20 cm.
Answers
Answered by
5
Explanation.
Radius of cone = 21 cm.
Height of cone = 20 cm.
C.S.A of cone = πrl
=> L = √h² + r²
=> L = √ ( 20)² + (21)²
=> L = √ 400 + 441
=> L = √ 841
=> L = 29
=> c.s.a = πrl
=> 22/7 X 21 X 29
=> 22 X 3 X 29
=> 1914 cm²
C.S.A of cone = 1914 cm²
some related formula.
1) = Volume of cuboid = L X B X H
2) = volume of cube = a³
3) = volume of cylinder = πr²h
4) = volume of cone = ⅓πr²h
5) = volume of hemisphere = ⅔πr³
6) = volume of sphere = 4/3πr³
Answered by
2
Step-by-step explanation:
Given
radius=21cm
height=20cm.
slant height=√r^2+h^2
=√21^2+20^2
=√441+400
=√841
=29cm
curved surface area of cone = πrl
=22/7x21x29
=1914cm^2
Similar questions