文[1]、文[2]、文[3]及文[4]对一个三角形重心向量性质进行了探讨,笔者阅读后深受启发,得到了三角形的一个向量性质,并进行空间拓广.图1三角形定理1如图1所示,已知△ABC及其内部一点P,若λ1PA+λ2PB+λ3PC=0,λ1,λ2,λ3都是大于0的实数,过P作直线AB,AC两边分别交于M,N两点,且A In [1], [2], [3], and [4], we discussed the nature of a triangle center of gravity vector. After reading this book, I was deeply inspired to obtain a vector property of a triangle and to expand it spatially. Figure 1 Triangle Theorem 1 As shown in Figure 1, it is known that △ABC and its internal point P, if λ1PA+λ2PB+λ3PC=0, λ1, λ2, and λ3 are all real numbers greater than 0, and P is the straight line AB and AC. Hand over to M, N two points, and A