Question

Barbed wire of length 76m is fixed to opposite corners of a square field. How long are the sides of the field? (from the Trigonometry chapter)

Answer 1

Step-by-step explanation:

Let ABCD represents the square field having each side of 20 mtr.

Let the cow is tied at point A by means of a 7 mtr long rope.

So the cow can move and gaze in the circular area having radius 7 mtr.

The maximum area that a cow can gaze is

=

4

1

πr

2

=

4

1

×

7

22

×(7)

2

=38.5sq.mtr

∴ The cow can gaze 38.5 sq. mtr are of the field.

If the length of the rope is doubled then r = 14 mtr.

The maximum area that a cow can gaze is

=

4

1

πr

2

=

4

1

×

7

22

×(14)

2

=154sq.mtr.

Increase in the gazing area = 154 - 38.5 = 115.5 sq. mtr

Increase in the gazing area is 115.5 sq. mtr.