3 First 0 degree Second 90 degree No I have 4 have equal parts. Third From the Centre height wise. (Z-axis) Now I have 8 equal parts.

With 4 straight cuts through 0, 45, 90, and 135 degrees You can cut the cake into 8 equal pieces

3 straight cuts

If the pie is real, then 4 cuts. If it is a hypothetical pie, then you can make one cut and then stack both of them on top of each other. Make another cut and repeat. At the third step, you will have 8 pieces

What shape is the cake? Don't assume. Gather data to inform your answer.

The question as phrased does not ask for doing it in the fewest cuts. If that is an acceptance criteria, you need to know going in.

^ Agreed. You can also think of it as stacking 'em up. Can be done in 3 cuts.

didn't expect this question, but I got the answer. You should think about it.