Here the length of the given side is 8, with an angle of 45[math]^\circ[/math] at either end (to start with).[br]The angles can be changed by moving D and E.[br]Move D around, then E. Notice what happens ...[br]What is the size of the angle at C?[br]Move A and B so that AB is horizontal. Adjust D and E to suit.[br]As you explore, notice which angles are acute, which are obtuse ... are there any right angles?[br]Write down everything your notice ...