Given that, a triangular field with the three corners of the field a cow, a buffalo and a horse are tied separatelp with ropes. So, each animal grazed the field in each corner of triangular field as a sectorial form.
Given, radius of each sectro ( r) = 7m
Now, area of sector with `angleC = (angleC)/(360^(@))xxpir^(2)=(angleC)/(360^(@))xxpixx(7)^(2) m^(2)`
Area of the sector with `angleB = (angleB)/(360^(@))xxpir^(2) = (angleB)/(360^(@))xxpixx(7)^(2)m^(2)`
and area of the sector with `angleH = (angleH)/(360^(@))xxpir^(2)=(angleH)/(360^(@))xxpixx(7)^(2)m^(2)`
Therfore, sum of the arese (in `cm^(2)` ) of the three sectors
`(angleC)/(360^(@))xxpixx(7)^(2)+(angleB)/(360^(@))xxpixx(7)^(2)+(angleH)/(360^(@))xxpixx(7)^(2)`
= `(angleC+angleB+angleH)/(360^(2))xxpixx49`.
= `(180^(@))/(360^(@))xx(22)/(7)xx49=11xx7 = 77 cm^(2)`
Given that, sides of triangle are a = 15,b = 16and c= 17
Now, spmi-perimeter of triangle, s = `(a+b+c)/(2)`
`rArr = (15 + 16 + 17)/(2) = (48)/(2) = 24`
`:.` Area of triangular field = `sqrt(s(s-a)(s-b)(s-c))` [by Heron's formula]
= `sqrt(24.9.8.7)`
= `sqrt(64. 9 . 21)`
= `8xx3 sqrt(21)=24sqrt(21)m^(2)`
So, area of the field which cannot be grazed by the three animals
= Area of triangular field - Area of each sectorial field
`24sqrt(21)-77m^(2)`
Hence, the required area of the field which can not be grazed by the three animals is `(24sqrt(21)-77)m^(2)`
