Since the paddock assumes a rectangular shape the area is 1/2 * b * h.
From Pythagorean AB^2 = BC^2 + AC^2
(3)^2 = (x + 0.4)^2 + x^2
9 = x^2 + 0.8x + 0.16 + x^2
So 2x^2 + 0.8x + 0.16 - 9 = 0
2x^2 +0.8x- 8.84 = 0
Using the quadratic formula
The solutions are 1.911 and -2.31
The area therefore is
area=1/2 * b * h
=1.91*2.31/2 = 2.21km²
1hectare = 0.01km²
2.21km^2 = 221ha
