Answer:
1: draw a line across the circle, but not through point O
2: place the two points on the edge of the circle so that the space in between is about 1/3 of the circle. Label C and D.
3: draw two lines out from point O to the edge of the circle. 45 is half of 90. this means you can draw a 90 degree angle and divide it in half and remove the extra line. Label these E and F.