Find the slant height and C.S.A of a cone whose volume is 12936 cm cube and the diameter of the base is 42 cm.
Answers
Answered by
51
Given,
Vol. of cone=12936cm^3
d=42cm
r=42/2=21cm
Vol. of cone=1/3πr^2h
12936=1/3×22/7×21×21×h
h=28cm
l^2=h^2+r^2
l^2=28^2+21^2
l^2=784+441
l^2=1225
l=35cm
CSA of cone=πrl
=22/7×21×35
=2310cm^2
Vol. of cone=12936cm^3
d=42cm
r=42/2=21cm
Vol. of cone=1/3πr^2h
12936=1/3×22/7×21×21×h
h=28cm
l^2=h^2+r^2
l^2=28^2+21^2
l^2=784+441
l^2=1225
l=35cm
CSA of cone=πrl
=22/7×21×35
=2310cm^2
Answered by
5
D=42 r=42/2 =21 cm
Volume of Cone = πr^2h
_________ 1/3×22/7 ×21×21×h=12936
__________________h= 28cm
_____________________________
Slant height of (l) =√(r^2 +h^2)
================= √(21×21 +28×28 )
==================35cm
_____________________________
CSA of Cone = πrl =22/7 ×21×35
=================2310 sq cm
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