With ActivInspire 1.5, when you draw a line using one of the Maths tools, the pen's behavior is changed to make it easier to draw lines to a specific length. This applies to the Ruler, Compass, Protractor and the new Set Square tools.
When you draw with the aid of a Maths tool, the line length remains variable until you lift the ActivPen.
The following example shows how it works, using the Pen tool with the Ruler to draw a line of length 50 units.