Fig. 34.
Fig. 35.
Fig. 36.
Fig. 37.
ANGLE is the difference in the direction of two lines which meet or tend to meet. The lines are called the sides and the point of meeting, the vertex of the lines.
To make an angle apparent, the two lines must meet in a point, as A B and A C, which meet in the point A, as shown in [fig. 33].