梯形是有两条边平行，其他两条边不平行的四边形。这表明梯形有两条边都可以当底。如果你想知道如何计算梯形的面积，那么按照下面的步骤来吧。
步骤
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1
确定两条底的长度。 底是梯形中两条平行的边。让我们把它们称为a和b吧。假如a边是8cm而边是13cm。
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2
把两条边相加。 把8cm和13cm相加，8 cm + 13 cm = 21 cm。
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3
确定梯形的高。 梯形的高是两条底之间的距离。在这个例子里，梯形的高是7cm。
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4
把梯形的高乘以两底之和。 两底之和是21出名，而高是7cm，21 cm x 7 cm = 147 cm2 。
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5
把结果除以2。 将147 cm2 初以2得到最后结果，147 cm2 /2 = 73.5 cm2 那么梯形的面积是73.5。这样你就可以知道梯形的面积公式是[(b1 + b2) x h]/2。