The angle between the lines represented by ax2+2hxy+by2=0ax^2 + 2hxy + by^2 = 0ax2+2hxy+by2=0 is given by:
tanθ=2h2−aba+b\tan \theta = \frac{2\sqrt{h^2 - ab}}{a+b}tanθ=a+b2h2−ab
tanθ=h2−aba+b\tan \theta = \frac{\sqrt{h^2 - ab}}{a+b}tanθ=a+bh2−ab
cosθ=a+b(a−b)2+4h2\cos \theta = \frac{a+b}{\sqrt{(a-b)^2 + 4h^2}}cosθ=(a−b)2+4h2a+b
sinθ=2ha+b\sin \theta = \frac{2h}{a+b}sinθ=a+b2h