A floral design on a floor is made up of 16 triangular tiles, each having sides 9cm, 28 cm and 35 cm. Find the cost of polishing the tiles at the rate of Rs. 2.50 per cm²

[Take =2.454]

Let the sides of triangle be 9 cm, 28 cm, and 35 cm

Semi perimeter,

Now, using Heron’s formula,

(Area of 1 tile)

= 88.2cm²

∴ Area of 16 tiles = 16 × area of one tile

= 16 × 88.2 cm²

= 1411.2 cm²

Now, cost of polishing 1cm² area = Rs 2.5

∴ Cost of polishing 1411.2 cm² = 2.5 × 1411.2 = Rs 3528