一天傍晚,狐狸娇娇带上一块铁皮,来到熊大伯的金属加工部。狐狸娇娇指着手中的正方形铁皮,对熊大伯说:“大伯,我妈妈需用15°的角,供角的度量使用。不过,我们惯用的三角尺上并没有15°的角,真烦人!现在,妈妈让我高薪请您用铁皮裁剪出一个15°的角,以解燃眉之急。” One evening, fox fondle a piece of metal, came to bear the metal processing department. The fox pointed at the square tinplate in his hand and said to him: “Uncle, my mom needs to use the angle of 15 ° for the measurement of the angle, but there is no angle of 15 ° on our conventional ruler. Annoying! Now, my mother asked me to pay you a cut of 15 degrees with a metal sheet in order to meet the urgent needs. ”