On the mathematics class, the teacher draws nine dots on the blackboard, and put them in the form of three rows. And he says to the classmates:“Here are nine dots, they are in three rows. If every three dots were linked by a straight line, how many lines can we draw at most.” Then the class begin to discuss warmly, and many students write or draw on the paper. Most of them draw “田” form with six straight lines in all. But Xiao Ming raises his hand and says:“I can draw ten straight lines.”Everybody feels very surprised. Now if you are Xiao Ming, how can you draw these ten straight lines?
点和线
数学课上,老师在黑板上画出了9个点,并把它们排成了3排。然后,他对同学们说:“这里有9个点,一共是三排。如果把每3个点用一条直线连起来,我们最多可以画几条这样的直线呢?”于是,同学们开始热烈讨论起来,还有不少人动手在纸上写写画画。大多数同学都画出了“田”字形,共有6条直线。可是,小明却举手说:“我能画出10条直线。”大家都感到非常地惊讶。现在,如果你是小明,会怎么画这10条直线呢?
小贴士:
mathematics 数学 classmate 同学 discuss讨论 |