Question: how do i solve this...physics

I have a physics problem that I hope to get help from this forum. The question is like this:

 I have figure here but I cannot paste it. Anyway I will try to make an explanation of where the points in the circle are located.

 A circle has a diameter from point BO (B the upper point, O the lower point). From the point O is another line, an inclined plane, point A, that extends to the right side of the half circle. If a particle is released in free fall along the vertical point BO, it uses the time t₁. Point A can lie anywhere in the side of the half circle. Show that if the particle slides along the inclined plane AO with out friction and without initial velocity, the time it uses, t₂,  is the same as the time it takes in free fall from B to A.

This question requires manual and maple solution. I am working on it and I am hoping to get help as well. Thank you in advance...

eiank