a decorative lamp is in the shape of cone mounted on sphere. If the radius and h of cone is 3cm and 4 cm. respectively.and radius of spherical part is 7cm find the area of the lamp which is to be painted?
Radius of the cone = r = 3 cm
Height of the cone = h = 4 cm
Radius of the sphere = R = 7 cm
Area which has to be painted = Area of sphere + Curved surface area of cone – Area of base of cone … (1)
Area of sphere = 
Curved surface area of cone = 
Area of base of cone = 
Put all the values in equation 1
Area which has to be painted = 616 + 47.143 – 28.28 cm2
= 634.863 cm2