Question

the total surface area of a cone having it's slant height 9dm & diameter of its base as 24dm is --​

Answer 1

Length = 24 m, breadth = 25 cm =0.25 m, height = 6m.

∴ Volume of cuboid = l x b x h

= (24 x 0.25 x 6) m3.

= 36 m3.

∴ Lateral surface area = 2(l + b) x h

= [2(24 +0.25) x 6] m2

= (2 x 24.25 x 6) m2

= 291 m2.

∴ Total surface area =2(lb+ bh + lh)

=2(24 x 0.25+0.25x 6 +24 x 6) m2

= 2(6+1.5+144) m2

= (2 x151.5) m2 

=303 m2.