RESPONSES to PUZZLE #7

Very few responses on this one, maybe that is good?

If you are still working on it, keep working.

Here is a hint:

As for the reasoning, here is one approach.

Notice that the sum of the measure of the interior angles

of the original quadrilateral is 360deg., since the sum of the

measure of the interior angles of a triangle is 180deg.?

Now look at the point P and the corners of the quadrilateral

which meet at P.

See anything interesting there?