单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,第二单元 角的度量,角的分类和画角,直角,钝角,锐角,直角,锐角,钝角,平角,周角,直角,锐角,钝角,周角,平角,角的特征,直角是,90,0,锐角小于,90,0,钝角大于,90,而小于,180,0,0,角的特征,30,0,60,0,90,0,120,0,150,0,180,0,平角是180,0,30,0,60,0,90,0,120,0,150,0,180,0,360,330,300,270,240,210,0,0,0,0,0,0,周角360,0,角的特征,周角是()度,90,90,180,360,180,锐角()度。,钝角大于()度,而小于()度,直角是()度,平角是()度,小于90,2个直角就是1(),3个45度的角是()角,2个45度的锐角是()角,1个周角就是()个直角,2个平角就是1个(),平角,周角,直,4,钝角,判断,1.,大于,90,度的角都叫钝角。(),2.,钝角都大于,90,度。(),3.,平角就是一条直线。(),且小于,180,度,30,0,1=,2+,4的和是多少?,3+,4,3,2,1,360 30 =330,0,0,0,30,0,0,90,0,60,三角板中的角度你知道吗?,是()角,,是()度。,120,钝,画出60度的角,60,0,画出150的角,0,