Question

80 m
50 m
A triangular park ABC has sides 120 m, 80 m and
50 m (as shown in the adjoining figure). A gardner
Dhania has to put a fence 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 20 per metre leaving a space 3 m
wide for a gate on one side.
3 m-
- 120 m
71​

Answer 1

QUESTION:-

A triangular park ABC has sides 120 m, 80 m and

50 m (as shown in the adjoining figure). A gardner

Dhania has to put a fence 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 20 per metre leaving a space 3 m

wide for a gate on one side.

▁ ▂ ▄ ▅ ▆ ▇ █ SOLUTION █ ▇ ▆ ▅ ▄ ▂ ▁

★GIVEN★

•SIDE OF TRIANGLE

•120M ,80M, 50M

★FIND:- AREA OF TRIANGLE AND IT'S PERIMETER

★ ACCORDING TO QUESTION★

*SIDE OF TRIANGLE

$↪ \frac{a + b + c}{2} \\ \\ ↪ \frac{120 +80 + 50 }{2} \\ \\ ↪ \frac{250}{2} = 125m$

*PERIMETER OF TRIANGLE=120+80+50

=250M

★AREA OF TRIANGLE★

$⇒ \sqrt{s(s - a) \times (s - b) \times (s - c)} \\ \\⇒ \sqrt{125(125 - 120) \times (125 - 80) \times (125 - 50)} \\ \\ ⇒ \sqrt{125 \times 5 \times 45 \times 75} \\ \\ ⇒ \sqrt{2,109,375} = 1452.36 {m}^{2}$

GIVEN, COST OF FENCING IT WITH BARBED WIRE AT THE RATE OF 2OM

PERIMETER OF FENCE=PERIMETER OF ∆-WIDE OF GATE

=250-3

=247M

HENCE:-

THE TOTAL COST OF FENCING=247*20

=₹4940

AREA NEEDED TO PLANT=1452.36m²