好像很简单的题目 gardener2022-09-25 04:34:59

Let S be a square, let M and N be the midpoints of two adjacent sides, and let V be the corner of the square that is opposite both M and N. Let θ be the measure of the angle between the two lines connecting M and N with V. Compute sin(θ) 

要求不能用三角函数公式

3/5

三角形等腰。三边容易求出。用面积公式即可算出顶角的正弦。