1, Garfield method.
Five years after Garfield proved this conclusion, he became the twentieth president of the United States, so people also called it the presidential certificate law. In the right trapezoid ABDE, it is proved that the variant of Garfield proof is the variant of Garfield proof. If you cut a big square with a side length of c diagonally, you will return to Garfield proof. On the contrary, if the two trapeziums in the above picture are put together, it becomes this proof method.
2. Zhao Shuang's string diagram.
It is a mystery that Pythagoras' shares are multiplied by each other. Prescription aside, it is metaphysics. The mysterious picture of the case can be multiplied by Pythagoras as Zhu Shi and multiplied by Zhu Shi. Multiply the Pythagorean difference by itself to be medium yellow. Adding the difference is also a mystery. Restore the truth with differences, and the remaining half. Take the difference as the method, write a prescription and get it back. Add the difference to the hook. Everything that is real is real. Either in an instant, or the square is outside. The shape is specious and the number is even, but the shape is different and the number is neat. The moment of hooking up is wide with the difference between stocks and metaphysics, and stocks and metaphysics are vast.
3. Qing and Zhu's visit map.
Blue Zhu diagram is a geometric proof method for mathematician Liu Hui to prove Pythagorean theorem by using the number-shape relationship according to the filling and excavation method in the late Eastern Han Dynasty. Very distinctive and easy to understand. Liu Hui described this picture, with the hook multiplied by Zhu Fang and the stock multiplied by Fang Qing. In this way, the entrance and exit complement each other and belong to their own categories, because the rest are still, and the power of chords is synthesized. In addition to prescription, string also. The general idea is that any right triangle with a red square hook width is called Zhu Fang and a blue square head is called Fang Qing.
4. Euclidean proof.
Euclid's Elements of Geometry gives the following proof of Pythagorean theorem. Let △ABC be a right triangle, where A is a right angle. Draw a straight line from point A to the opposite side so that it is perpendicular to the opposite side. Extending this line divides the opposite square into two, and its area is equal to the other two squares. In the proof of this theorem, we need the following four auxiliary theorems: If two triangles have two sets of corresponding sides and the included angle between the two sets of sides is equal, then the two triangles are congruent.