Question

A triangular park ABC has sides 120cm, 80m and 50m. A Gardener Dhania 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 metre leaving a space 3m wide for a gate on one side.

Answer 1

area needed to plant grass is
120×80×50=480000 metre square
total length for fencing is
=120+80+50=250-3=247 metre
rs 20 for 1 metre
so for 247 metre rs =247×20=Rs4940

Answer 2

area for growing grass = area of triangle
s=a+b+c/2
s=120+80+50/2
s=250/2
=125

area=√s(s-a)(s-b)(s-c)
=√125(5)(45)(75)
=1452.36m^2
fencing area = perimeter-3 metre
120+50+80-3
=250-3
=247m
cost of fencing
=20×247
=4940 rs