Question

A floral design on a floor is made up of 16 tiles which are triangular, the sides of the triangle being 9cm, 28cm and 35cm. Find the cost of polishing the tiles at the rate of 50p per $c{m}^2$.

Answer 1

Area of tiles = 16 x area of 1 $\Delta$

$S=\frac{a+b+c}{2}=\frac{9+28+35}{2}=\frac{72}{2}=36$

$Area=\sqrt{36(36-9)(36-28)(36-35)}$

$\sqrt{36\times 27\times 8\times 1}$

$36\sqrt{6}c{m}^2$

Area of tiles = 16 $\times 36\sqrt{6}$

=$\mathrm{1410.20.}$

Cost of polishing per $c{m}^2$ = 50.

Cost of polishing = $1410.90$ $c{m}^2$

$1410.90$ x $\frac{1}{2}$

$705.45$