Test your knowledge of the measurement of angles in a triangle.

Determine the missing angle measures of quadrilaterals inscribed in circles.

Determine the rules for radius and tangents of circles.

Use the alternate segment rule for cirlces to determine the angle measures.

[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine missing angles in a parallelogram.

This site, which is provided for by the University of St Andrews, contains brief biographical information on Jean Robert Argand. Many interesting links at the bottom of the site.

[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on finding the missing angles in a trapezoid.

This site offers numerous activities for middle school and high school students to explore using Geometer's Sketch Pad.

This lesson will demonstrate the use of CPCTC in triangle congruencey proofs. It is 2 of 4 in the series titled "CPCTC."

Formulas and illustrations show the different kinds of angles created by intersecting tangents, secants, radii, and in combination.