Given the length of one side of a triangle and two angles (one at each end of the given side), construct it.

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