1. Open the proof in Spark! if it is not already open.
2. Click the Measurement tool in the Spark! toolbar.

3. Drag the mouse from one point to another to measure the distance.

You can hold the Shift key to make the Measurement tool snap to 90º and 45º angles.

The measurement display will show you the distance and angle of the measurement.

Units of measurement can be changed by clicking the units indicator in the measurement display and selecting either inches, centimeters, or pixels.

To delete the measurement, click the blue X in the upper-right corner of the black measurement box.