3.There are 81 grid points(uniformly spaced) in the square shown in the diagram below,including the points on the edges.Point P is the center of the square.Given that point Q is randomly chosen from among the other 80 points,what is the probability that the line PQ is a line of symmetry for the square?( ?。?br />如圖所示的正方形內(nèi)有81個(gè)網(wǎng)格點(diǎn)(均勻分布),包括邊緣上的點(diǎn)。點(diǎn)P是正方形的中心。若從其他80個(gè)點(diǎn)中隨機(jī)選擇定點(diǎn)Q,那么線(xiàn)PQ是正方形的對(duì)稱(chēng)線(xiàn)的概率是多少?( ?。?/div>
發(fā)布:2024/9/7 2:0:9組卷:11引用:1難度:0.5