义务教育教科书(人教版)数学四年级上册角 的 度 量执教:云南省昭通市实验小学 彭国群生活中的角生活中的角顶点边 1234567891011121314151617181°1°1° 10°10° 5° 25° 55° 125° 403020107060805090100110120130140150160170018050° 403020107060805090100110120130140150160170018030° 403020107060805090100110120130140150160170102030405060708010011012013014015016017001801800中心点0° 刻度线 403020107060805090100110120130140150160170102030405060708010011012013014015016017001801800内圈刻度外圈刻度中心点0° 刻度线小组合作量一量下面的角,并在小组中讨论:用量角器量角要注意哪几点?