Plane angle
01
平面角, 二面角
the measure of the tilt between two lines or surfaces in two-dimensional space, typically given in degrees or radians
例子
The clock 's hands form a plane angle at noon.
时钟的指针在中午形成一个平面角。
A corner of a book forms a right plane angle.
书的一角形成一个直角平面角。
