Draw a straight line
To draw a straight line with the Pen tool
In the Tools panel, click Pen.
On the artboard, click once to define the start point, and then click again to define the end point of the line.
Tip
To constrain the angle of the line to multiples of 45 degrees, hold SHIFT when you click to define the end point of the line.
To draw a straight line with the Line tool
In the Tools panel, click Line .
Drag from where you want the line to start and release at the point where you want the line to end.
Tip
To constrain the angle of the line to multiples of 15 degrees, hold SHIFT while drawing the line.