164000

We know that every angle in a square is 90° and there are only 2 diagonal lines which can fit in the square(making 4 separate triangles). When you draw the diagonal line, the corners would now be split into 45° each. We know that a triangle adds up to 180° and two of the angles are 45° each, hence the third angle (where the diagonal lines are intersecting) is 90°{180°-(45°+45°)}. Now the Mathematician will know that the diagonal lines will always meet up to 90°.