本文结合实际例子,阐明直角三角形在解题中的妙用.一、隐藏的直角三角形例1在5×5的正方形网格中,ABC的顶点都在格点上,如图1所示,求BC边上的高是多少?ACB图1%分析与思考计算边长后我们可以判定ABC是直角三角形.这样我们就可以再利用面积求出斜边BC上的高来了.易得BC边上的高是h=槡102.此例中我们必须首先判断出ABC是直角三角形,即把隐藏的直角三角形 In this paper, the actual examples, clarify the right triangle in the problem-solving magical effect.First, the hidden right triangle Example 1 In a 5 × 5 square grid, ABC’s vertices are in the grid, as shown in Figure 1, seeking BC ACB Figure 1% Analysis and Thinking After calculating the side length, we can determine that ABC is a right-angled triangle, so that we can re-use the area to find the height of the hypotenuse BC to come. High is h = 槡 102. In this case we must first determine that ABC is a right-angled triangle, that is, the hidden right-angled triangle