角的度量,西南师大版四年级数学,,,,,,,,,,,,,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,角,顶点,边,边,,,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,,,,角,顶点,边,边,0,,4 厘米,,,,,,3厘米,4 厘米,,,,,12 平方厘米,,,,,,,,,0,,,,,,中心点,量角器,,,0刻度线,0刻度线,0,0,,,1度,1°,,,,,,0°,10°,20°,30°,40°,180°,170°,160°,150°,140°,130°,120°,110°,100°,90°,80°,70°,60°,50°,0°,10°,20°,30°,40°,180°,170°,160°,150°,140°,130°,120°,110°,100°,90°,80°,70°,60°,50°,,,50°,,0刻度线,中心点,,,0°,10°,20°,30°,40°,50°,,,130°,,0刻度线,中心点,,,80°,,,,,84°,,,63°,,,,,,,67°,67°,,,,42°,,,,,,,,,,,8°,。