Question

A triangular park has sides 120 m, 80 m and 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 metre, leaving a space of 3 m wide for a gate on one side.​

Answer 1

Answer:

P (perimeter)= 120+ 80+ 50/ 2 = 250m

Area = √s (s-a) (s-b) (s-c)

a= 120m

b= 80m

c= 50m

area= √250 ( 250-120) (250-80) (250-50)

= √250× 130× 170× 200

= √2×5×5×5×2×5×13×2×5×17×2×2×2×5×5

= 2×5×5×2×2×5 √13×5×17

= 10×10×10 √ 272

= 1000√ 272

= 1000 √ 2×2×2×2×17

= 1000 ×2×2 √ 17

= 4000 √ 17

= 4000 × 1.26

= 5040m3.

the cost of fencing it with barbed wire at the rate = 5040×20/3

= 1680× 20

= 33600m3.

hope it help you