Investigating Geometry with GeoGebra

Henrico County Public Schools

Protractor - Measure Angles

READ the instruction below and INTERACT with the GeoGebra applet on the right.

  1. The blue point moves the protractor.

  2. The red point rotates the protractor.

  3. Use the protractor to measure the eight labeled angles.

  4. Why do you not have to measure the two unlabeled angles? What are their measures?
Sorry, the GeoGebra Applet could not be started. Please install Java 1.4 (or later) to use this page.