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 value of a + b + √2 c equal to ?

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: