In the calculation of right-angled triangle edges, it is often necessary to set an unknown number, and then use Pythagorean theorem to solve equations (groups). Sometimes, in the case of complex graphics or chaotic topic relationships, we can draw a schematic diagram to help expand our thinking. For example, in Example 2 below, because we lack the height line we are familiar with when calculating the triangle area, we can first fill an auxiliary line on the map as the height of an edge, and then list the solutions according to the area formula and the relationship between the edge and the height line.
In the third example, we met a problem and gave some conditional relations, which are also very suitable for the equation, and even the equation appears here. However, according to the area formula, we cleverly found that this problem does not need two right-angled sides, that is to say, it does not need what X and Y are respectively, which reduces the amount of calculation. After all, the relation 1/2xy is an area formula of a triangle, which belongs to a small place that can be tricky.
Example 4 looks more like an array relationship at first glance, but when we deeply understand the relationship between the three sides of a triangle, especially a right triangle, we can first determine the length of the hypotenuse (the longest side) n+3, and then use Pythagorean theorem to solve it. Then, after calculating the result, it is necessary to discuss the trade-off, and the conditional judgment of the trade-off is side length >; 0。
Pythagorean theorem belongs to basic geometric knowledge, which can be applied to examination papers until the end of college entrance examination, and even to scientific research and industrial application in the future. Treat it well, then get familiar with it and master it!