Question

From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid to the nearest `c m^2`

Answer 1

Total surface area=`pir^2+2pirh+pirl`
=`pir^2+2pirh+pir sqrt(r^2+h^2)`
=`pir(r+2h+sqrt(r^2+h^2))`
=`22/7(0.7)(0.7+4.8+sqrt(2.4^2+0.7^2))`
=2.2(5.5+2.5)
=`17.6 cm^2`