2 math questions from BB 2nd edition

fogcity
Tue, 26 Jul 2011 19:10:16 +0000

For the first problem, look carefully at the right triangle to which you’re applying the Pythagoras theorem. The hypotenuse is an edge (length m), and the base is 1/2 the diagonal of the square. You have to apply the Pythagoras theorem twice. First to obtain the base of the triangle (which is 1/2 the diagonal of the square), and a second time to obtain the height.

The diagonal of the square is m sqrt(2). The base is the 1/2 of that. Now apply the Pythagoars theorem to get the height of the traingle. You get height = sqrt (mm - mm/2).

Your error is that you took 1/2 the side of the square as the base of the triangle instead of the 1/2 the diagonal.