<p>I think, il bandito asked (#153) about solving a modified problem (#152) - when the ball is thrown 45 deg. to the horisontal, and it's a totally different ball game: a trajectory becomes a curve.</p>
<p>If you count the number of edges, you'd get 12. If you count the number of vertices times 3 (for 3 right angles/vertex), you'd get 24. The second number is double the first number because in effect, each edge is connected to two vertices.</p>
<p>aghhh i am not sure abt this but i m getting 16 as the answer for that ques.</p>
<p>nm i didn't consider all the edges</p>
<ol>
<li><p>How many 60 deg. angles are formed by the edges of a tetrahedron (a pyramid that has 4 equilateral triangles as faces).</p></li>
<li><p>How many 45 deg. angles are formed by the edges and all the diagonals of a cube?</p></li>
<li><p>How many 90 deg. angles are formed by all the diagonals of a cube?</p></li>
</ol>