Question

the radius of base of a cone is 12cm and slant height is 20cm. find its total surface are. (π = 3.14)​

Answer 1

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$\bold{Explanation:}$

R.E.F image

OA=16cm,AB=l

l=

16

2

+12

2

=

256+144

l=20cm

curved surface Area,

C.S.A=πrl=3.14×12×20=753.6cm

2

Total surface Area,

T.S.A=πr(r+l)=3.14×12[12+20]=1205.76cm

2