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 of polishing the tiles at the rate of 50 p per cm2.

Given:⇒a=35cm,b=28cm,c=9cm⇒Semi perimeter of tile=a+b+c/2⇒Semi perimeter of tile=35+28+9/2=36cm⇒Area ofΔ=√s(s−a)(s−b)(s−c)⇒=√36(36-35)(36-28)(36-9)⇒=√36×1×8×27⇒=36×2.45=88.2 cm2⇒Area of total 16 tiles=16×88.2=1411.2 cm2⇒Cost of polishing per cm2 area=50p⇒Cost of polishing 1411.2 cm2 area=Rs. 50×1411.2=Rs. 705.60