Draw a perpendicular line from a fraction of a line (e.g. ¼)

Do you want to draw a perpendicular line, not from the start or endpoint of a line, but exactly at a percentage of its length? In Pythagoras this is easy to do — for example at 25%, 50%, or 75% of a line.

Workflow

1. Click the drawing function  Perpendicular Line/Arc.

2. Click the existing line where you want to draw the perpendicular. An icon appears on the line.

3. Hold down the 4 key on the numeric keypad and move the cursor along the line until the indicator 1/n appears, then click. (This appears at 1/4, 2/4, 3/4, etc. of the line).

4. Release the numeric key. The cursor is now locked exactly at that fraction of the line.

5. Move the cursor away from the existing line.
   Do you want a tangential arc instead of a straight line? → Press SPACE.

6. Click to place the endpoint.
   Refine in the Control Panel:

   • In the field L (length from start point to endpoint of the perpendicular), type the desired length.

   • In the field R (radius of the arc), type the desired radius.

7. Press ENTER to finish the perpendicular or arc.

You can use not only 4 (¼), but also 2 (½), 3 (⅓), 5 (⅕), etc. The system always calculates 1/n of the line length. This way you can snap to any fraction of the line, as long as you press the corresponding key.

Tip

• You can also use this numeric shortcut without the perpendicular function.

• You can check the total length of a line by hovering over it with your cursor — the value appears in the Control Panel under the label L.