有一位老师教学《长方形、正方形和平行四边形》的方法颇具特色。他首先向学生出示如下图形: 他首先向学生出示如下图形:①②并说明这些图形和(数学)第四册(五年制)第116页一118页的图一样,让学生数一数它们的边数,问:“他们各是几边形?”学生很快答出是四边形。接着,他让学生在课本中度量这些四边形相对的边长,问:“哪些四边形的相对边 A teacher teaching ”rectangular, square and parallelogram“ method is quite distinctive. He first presents the student with the following graphic: He first presents the student with the following graphic: ① ② and shows that the graphic is the same as the figure on page 116-118 of the (Math) Volume IV (five-year) Number of sides, ask: ”They are each polygons?“ ”The students quickly got out of the quadrilateral. He then asked the students to measure the relative lengths of these quadrilaterals in the textbook and asked: "Which quadrilateral opposite sides