Question

Find the cost of laying grass in a triangular field of sides 50 m, 65 m and 65 m at the rate of Rs 7 per m².

Answer 1

Given: The sides of the ground are a = 50 m, b = 65 m and c = 65 m.

Now, the semi-parameter(s) of the cost of levelling is:

2s = a + b + c

2s = 50 m + 65 m + 65 m

2s = 180 m

`s = (180 m)/2`

s = 90 m

Area of triangle = `sqrt(s(s - a)(s - b)(s - c))`

= `sqrt(90(90 - 50)(90 - 65)(90 - 65))`

= `sqrt(90 xx 40 xx 25 xx 25)`

= 3 × 2 × 10 × 25

= 6 × 250

= 1500 m²

The cost of laying grass 1 m² area is Rs. 7.

Therefore, the cost of levelling grass per 1500 m² = Rs. 7 × 1500 = Rs. 10500