The Pythagorean Theorem

The Pythagorean Theorem. Kepler once says: "The Pythagorean Theorem and the Golden Ratio is two of the greatest discoveries in Geometry". Do you know Pythagoras Theorem is also known as the Pythagorean Theorem, 100 oxen Theorem, Gou Gu Theorem, Shang Gao Theorem, Chen Zi Theorem, Lu Qiao Theorem? Do you know there are about 400 different methods to proof this theorem?