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 figure). Find the cost polishing the tiles at the rate of Rs.50 paise per ${cm}^{2}$ .

Given,

the sides of a triangular tile are 9 cm, 28 cm and 35 cm.

For each triangular tile, we have,

Now, Area of triangle

=

(Since, Heron's formula [area =

=

=

=

=

= 16 ×

= 16 × 36 × 2.45

Total cost of ploshing the titles at the rate of Rs.50 paise per

= Rs.