After the hypotenuse is divided, the triangle can be divided into nine small triangles, and the square in the triangle accounts for four parts, so that the area can be calculated.

As long as the upper shadow line is rotated 90 degrees counterclockwise with the two vertices of' Gong * * * *, you will find that the S Yin becomes a right triangle with 8 and 4 on the right, and the Yin =4X8÷2= 16.

trait

In addition to the properties of the general triangle, it also has some special properties:

1, the sum of squares of two right angles of a right triangle is equal to the square of the hypotenuse. As shown in figure 2, ∠ BAC = 90, then AB? +AC？ =BC？ (Pythagorean theorem)

2. In a right triangle, two acute angles are complementary. As shown in Figure 2, if ∠ BAC = 90, ∠ B+∠ C = 90.

3. In a right triangle, the median line on the hypotenuse is equal to half of the hypotenuse (that is, the outer center of the right triangle is located at the midpoint of the hypotenuse, and the radius of the circumscribed circle R=C/2). This property is called the hypotenuse midline theorem of right triangle.

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