西摩松定理告诉我们 ,三角形外接圆上任意一点在三角形三边上的射影是共线的(这条线叫西摩松线 ) .下面我们将要考虑的是 :在三角形三边上的射影共线的点 ,是否一定在三角形的外接圆上 ,即西摩松定理的逆命题是否为真 ?定理　如果一点在三角形三边上的射影共线 ,那么这点必在该 The Seymourson theorem tells us that any point on the triangle’s circumcircle is collinear on the three sides of the triangle (this line is called the Seymourson line). Here we will consider the following: Is the point of the line necessarily on the circumcircle of the triangle, that is, whether the inverse proposition of Seymours’ theorem is true? If the theorem is a projective collinear on the three sides of the triangle, then this point must be