A floral design on a floor is made up of 16 tiles which are triangular, the sides of the triangle being 9 cm, 28 cm and 35 cm (see Fig. 12.18). Find the cost of polishing the tiles at the rate of 50p per cm2

Perimeter of each triangular shaped tiles = 28 + 9 + 35

Semi perimeter of each triangular shaped tiles =


=


= 36cm


Now,


Using Heron’s formula,


Area of =


=


=


= cm2


= 88.2cm2


Total area of 16 tiles = 16*88.2 cm2 = 1411.2 cm2


Rate of polishing tiles = 50p per cm2


Hence,


Total cost of polishing tiles = Rs. 705.6


10