Thales's theorem (Year 7)

Thales's theorem states that every angle inscribed in a semicircle over the diameter is a right angle. Using the Thales circle you can construct a right triangle over a given hypotenuse and a tangent from an external point. Exercises live under the German Klasse 7 (Satz des Thales is an explicit KMK Klasse 7 requirement); EN gets an introduction article only.