A square has four right angles (90°). Each diagonal splits a corner into two angles of 45°. Note also that the diagonals cut each other in half at right angles. A rectangle has four right angles.

A right angle is 90° or a quarter turn. It looks like the corner of a square or rectangle. You can spot right angles in doors, books or the edge of a piece of paper. An acute angle is less than 90°.

You'll like draw a perfect square or rectangle by drawing congruent angles to form the box, and then congruent triangles (equilateral triangles) form the pitched roof. An easy way to remember ...