Thread: circle geometry urgent

the question states

A,B and C are points on a circle with centre O. AO is parallel to BC. AC and BO intersect at D. angle BDC = 105 degrees. find the size of angle BCA.

i have drawn the picture im jus finding it difficult as to where to start :S
your help will be much appreciated cause i have spent numerous hours on this question

thanks heaps
xx

Here are some hints for you.

You will need to use:

Opposite angles are equal
Alternate angles of parallel lines are equal
Angle at centre is twice the angle at the circumference
Angle sum of triangle.

If you don't know an angle, you can make that angle = x (a variable)

Does it help?

hey thanks i will try that