How do I draw a line to an exact length, angle or coordinate with the Draw Line (polyline) tool?

Three ways to place an exact point

The Draw Line tool accepts exact values from the keyboard while you draw, from the form, or (in 12.5) from on-screen entry modes in the 3D view.

1. Quick keys while drawing

With a line in progress, point the mouse in the direction you want, then type:

• A single value, then Enter: adds the next point that distance along the direction the mouse is pointing. Example: 3.5 Enter.
• Two values with a comma, then Enter: places the next point at that absolute X, Y position. Example: 1,2.5 Enter.
• Angle and length: value A value L. Example: 45A3L makes a segment at 45 degrees, 3 units long, from the last point.

2. The Next Point section of the form

Enter either the absolute X Y position, the Angle and Length, or the relative offset dx and dy, then click Add. X Y is absolute. Angle, Length and dx/dy are measured from the current point.

3. Arrow-key modes (12.5)

The What's New page describes using the arrow keys to cycle the entry mode between length, length plus angle, absolute XY and relative XY, so points can be typed in the 3D view without using the form.

Keys that finish or fix a line

• Space: finish this line, keep the tool open for another.
• Right-click or Esc: finish and exit.
• Tab: close the vector back to its start.
• Backspace or the Undo button: remove the last point.
• S: switch between straight and curved segments. Click and drag instead of clicking to pull out a smooth curve.
• T: with the cursor over an arc, make the line tangent to it. Tangents work with arcs, not Bezier curves, and the arc is not trimmed.

Extend an existing open vector

Hover over its end point, hold Ctrl, press the left mouse button near the point and drag to draw onward.

Gotchas

• A single typed value follows the mouse direction, so a slightly off-axis mouse gives a slightly off-axis line. Use the angle and length form (0A3L) or snapping when the direction must be exact.
• The tool remembers whether you last used straight or curve mode, even after closing the software. If your first click starts a curve, press S.

Pro tips

• Clicking close to the first point snaps the shape closed.
• See the entry on snapping and guide lines for locking directions without typing.