A circle of diameter D has a point P internally.

From this point three lines at 120 degree spacing radiate to the circumference of the circle.

One area so formed is a quarter of the total area of the circle, whilst another is one third of the total area of the circle.

In terms of D, find an expression for the distance between P and the centre of the circle.

I've been "playing" with that for a while; keep getting UGLY stuff.

Anybody see any "shortcuts"? Thank you.