Below you can see a triangle inscribed into a semi-circle, illustrating the so called [i]Theorem of Thales[/i].
Move point [i][color=#0000ff][b]C[/b][/color][/i] along the semicircle. Can you come up with an assumption about the [color=#38761d][b]angles[/b][/color] in this triangle? [br]Check your assumption for different triangles by moving points [i][b][color=#0000ff]A[/color][/b][/i] and [i][b][color=#0000ff]B[/color][/b][/i].