摘要
1.Problems posed It is well known that the area formula of a square is the length of one of its sides multiplied by the length of its another side,and that the area formula of a rectangle is its length multiplied by its width,and the that the area formula of a trapezoid is the sum of its top side plus its base side(or we may say“its bottom”)divided by 2 and then multiplied by its height,and that the area formula of a triangle is its base side multiplied by its height and then divided by 2.However,how do all these area formulas come from?Have you ever thought of this question?
