What we know:
(Also,
)
What we need to solve:
(This is equal to
)
How you have to subtract
with
to get:

Thus, the answer would be:

This is more or less how you write the question.

To solve it invert the 1/2 and multiply.

Which gives you 14 /8 whis is 1 3/4 cups.
No its not polygons dont cross lines