Question

The sides of triangular field are in the ratio 5:3:4 and its perimeter is 180cm.find the cost of levelling at the rate of rs10per square metre

Answer 1

Answer:

Let the sides be 5x, 3x and 4x.

Perimeter = Sum of all sides

= 5x + 3x + 4x = 180

= 12x= 180

= 180/12 = 15

Hence,the sides are 75, 45 and 60.

Area using Heron's formula = √s(s-a)(s-b)(s-c)

Where s = semi perimeter and a,b and c are the sides.

= S = 180/2 = 90

= √90(90-75)(90-45)(90-60)

= √ 90 × 15 × 45 × 30

= √1822500 = 1350 cm square = 0.135 metre square

Rate of levelling → Rs 10/metre square

Cost of levelling = 10 × 0.135 = Rupees 1.35