Hence, of all the rectangles inscribed in the given circle, the square has the maximum area.
Equations of the lines are y = 2x + 1, y = 3x + 1 and x + 4
Let y1 = 2x + 1, y2 = 3x + 1
Now area of the triangle bounded by the given lines,
=

4

‌

0

(y2−y1) dx
=

4

‌

0

[(3x+1)−(2x+1)] dx
=

4

‌

0

x dx
=

1

2

[x2]04
=

1

2

(42−02)
=

1

2

× 16
= 8 sq. units
Thus, the area of the required triangular region is 8 square units.