Question

A triangular park has sides 120m, 80m and 50m. A gardener has to

put a fence all around it and also plant grass inside. How much area

does she need to plant? Find the cost of fencing it with barbed wire

at the rate of Rs.20 per meter, leaving a space of 3m wide for a gate

on one side.​

Answer 1

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