C40 He Would Only Die If He Mocked a Bookworm

The first question is the proof of numbers, value (15), on the paper, there is a column with a triangle embedded in it, requesting to prove the center point of the triangle, perpendicular to the center point of the column.

The second question was the conical analysis (25 points)...

The third question, proof that the cube was propendicular to the surface (35 points)...

The fourth question..