# Angle between straight lines

The angle between two intersecting lines is the value of the smallest plane angle at the intersection of these lines. If two straight lines are parallel, then the angle between them is assumed to be zero. The angle between two intersecting straight lines is the smallest angle (sharp) formed at the intersection of these lines.

**Angle between straight lines**

**Enter the equations of the lines**

**x +**

**y +**

**= 0**

**и**

**x +**

**y +**

**= 0**