Consider the following for the next items that follow:

The angles A, B and C of a triangle ABC are in the ratio 3 ∶ 5 ∶ 4.

What is the ratio of a2 ∶ b2 ∶ c2 ?

What is the equation of directrix of parabola y2 = 4bx, where b < 0 and b2 + b - 2 = 0?

The points (-a, -b), (0, 0), (a, b) and (a2, ab) are:

Given that 16p2 + 49q2 - 4r2 - 56pq = 0. Which one of the following is a point on a pair of straight lines (px + qy + r) (px + qy - r) = 0?