11. A gardener has to put double fence all around a triangular field with sides 120 m, 80 m and 60
m. In the middle of each of the sides, there is a gate of width 10 m.
(i) Find the length of wire needed for fencing
(ii) Find the cost of fencing at the rate of ? 6 per metre
(ill) Find the area of triangular field
Answers
The length of the wire needed for the fence is 460 m.
Given : A gardener has to put a double fence all around a triangular path with sides 120m, 80m and 60m.
In the middle of each side there is a gate of width 10m.
The perimeter of triangle = Sum of all sides
= 120+80+60 = 260 m
Now , the length of wire needed for fence = 2 x [Perimeter of triangle - 3(10)]
= 2 x(260-30) = 2 x (230) = 460 m
Therefore , the length of the wire needed for the fence is 460 m.
Cost of fencing at the rate= Rs.6 per metre
= 6×460
Cost of fencing at the rate = 2,760
Area of triangular field = A=√s(s﹣a)(s﹣b)(s﹣c)
s=a+b+c/2
Solving for A
A= 1/4√-a⁴+ 2(a b)²+2(ac)²﹣b⁴+2(bc)²﹣c⁴
= 1/4√﹣120⁴+2·(120·80)²+2·(120·60)²﹣80⁴+2·(80·60)²﹣60⁴
= 2133.0729m²
Answer:
Answer
Step-by-step explanation:
answer is solved in the pictures attached answer verified from reliable too .
