人教版七年级上册数学教科书第138页有这样一道练习题:6时整,钟表的时针和分针构成多少度的角?8时呢?8时30分呢?这是一道与钟面上时针、分针的夹角有关的问题,对于这类问题,不少同学总是感到束手无策,难以下笔.事实上,要想正确求解,就要先了 PEP 7th grade mathematics textbook page 138 has such an exercise: 6 o'clock, watch hour and minute hands constitute the angle of how many degrees? 8:00? 8:30? This is a clock with the clock face , The angle of the minute hand related issues, for such issues, many students always feel helpless and difficult to write down.In fact, in order to correct the solution, we must first