Question

The sides of a triangular field are 120 m, 160 m and 200 m. Then the cost of ploughing it at 25 paise per sq. m is​

Answer 1

Step-by-step explanation:

Now we find area of triangular field by using Heron's formula .

We know Heron's formula :

Area of triangle = s(s −a)(s −b)(s −c)−−−−−−−−−−−−−−−−−−√

Here s = a + b + c2 and a = 200 b = 150 and c = 120

So ,

s = 200 + 150 + 1202 = 4702 = 235 cm

Then

Area of triangular field = 235(235 −200)(235 −150)(235 −120)−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−√ = 235 × 35 × 85 ×115−−−−−−−−−−−−−−−−−−√ = 80399375−−−−−−−−√ = 8966.569 ≈8966.57 cm2

Rate of ploughing the field at 50 paise per square cm .

So,

Cost of ploughing the field = 50 × 8966.57 = 448328.5 paise = 4483.285 = Rs .4483.30 ( Ans