2s=50m.80m.120m find the area of place. …

Question : A triangular park has sides 120 m, 80 m, 50 m. A gardener has to put a fence all around it and also plant grass inside. How much area does he need to plant? Find the cost of fencing it with barbed wire at the rate of Rs 20 per meter leaving a space 3 m wide for a gate on one side.

Answer:

Area to be planted 

Cost of the fencing = Rs.4940

Step-by-step explanation:

Given : A triangular park has side 120m ,80m, 50m.

Barbed wire at rate of Rs.20 per meter.

To find : The area of park he need to plant and the cost of fencing leaving a space of 3m wide for a gate on 1 side.

Solution : First we the area by Heron's formula,

Where s is 

a= 120m, b=80m, c=50m

Substitute the value,

Now, The area to be planted is

Length of the fenced = Perimeter- space for the gate

Perimeter= a+b+c= 120+80+50=250

Space for the gate is = 3m

Length of the fenced = 250-3 = 247 m

Cost of the fencing = Length of the fence × Wire rate

Cost of the fencing = 247 × 20 = Rs.4940