第2单元 第1课时 多边形的认识（课件PPT）-【优翼·学练优】2022-2023学年二年级数学上册同步备课（苏教版）

苏教版二年级上册 多边形的认识 第二单元·平行四边形的初步认识 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 情境导入 你能从中找出边数相同的图形吗？在图中描一描。 下面是我国古代建筑上一种常见的窗格图案。 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 新知探究 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 新知探究 像这样有4条边的图形是四边形。 长方形和正方形都是几边形？ 1 2 3 4 1 2 3 4 四边形。 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 新知探究 这两个图形各有5条边，是五边形。 1 2 3 4 5 1 2 3 4 5 下面的图形各有几条边？是几边形呢？ www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 新知探究 这两个图形各有6条边，是六边形。 1 2 3 4 5 6 1 2 3 4 5 6 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 新知探究 由4条边围成的封闭图形是四边形； 由5条边围成的封闭图形是五边形； 由6条边围成的封闭图形是六边形； 由几条边围成的封闭图形就是几边形。 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 想想做做 1 2 3 4 1 . 在四边形下面的（ ）里画“√”。 （ ） （ ） （ ） （ ） 1 2 3 4 1 2 3 4 1 2 3 √ √ √ www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 想想做做 2.钉子板上围出的各是什么图形？你能围出四边形、五边形和六边形吗？ 四边形 五边形 六边形 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 想