Question

Find out the curved surface area of cone. if the height is 16 cm and base radius is 3/4 of the height and also find out total surface area.

Answer 1

given height (h)=16cm
radius (r)=3/4h=3/4 x 16=12 cm
slant height(l) =root {(16)^2+(12)^2}=20cm

now curve surface area=pi.r.l
=22/7 x 12 x 20cm^2
=753.6cm^2
now
total surface area =curve surface area+base area =753.6cm^2+22/7 x (12)^2
=753.6cm^2+452.16cm^2=1205.76cm^2

Answer 2

curved surface area =pi*r*l=22/7*12*20=754.3 cm^2
total surface area =pi*r (r+l)=22/7*12 (12+20)
=1206.86 cm^2
where l=root (h^2+r^2) (l IS THE SLANT HEIGHT)
where r=3/4*16=12