[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to construct perpendicular bisectors and use the Perpendicular Bisector Theorem.

This site describes the role of computer involvement in the four color map theorem.

This site defines what a locus is and offers links to five locus theorems. Walks you through the six "Steps to solving a locus problem."

A comprehensive guide for learning all about chords of a circle with definitions, chords of a circle theorems, intersecting chords theorem, congruent circles, diameter, solved examples, and practice questions.

Use these resources in preparing instruction on undefined terms (points, lines, and planes), theorems relating lines and planes, and Euclidean and non-Euclidean geometry. You'll find three lessons on the aforementioned subject areas, an...

This site defines a locus and introduces five theorems about loci. Click on the "Topic Index" link to find related practice activities and resources.

This tutorial has students investigate the second of the locus theorems. Click on the "Topic Index" link to find related practice activities and resources.

Use this site to investigate the third theorem of loci, equidistant from two points. Click on the "Topic Index" link to find related practice activities and resources.

Use this site to learn about the fourth locus theorem regarding parallel lines. Click on the "Topic Index" link to find related practice activities and resources.

The fifth theorem of loci is investigated on this site. Click on the "Topic Index" link to find related practice activities and resources.

This mini-lesson explores the world of the midsegment of a triangle by finding the answers to questions like what is midsegment of a triangle, triangle midsegment theorem, and proof with the help of interactive questions.

Learn all about the basic properties of a cone. This lesson targets the ASA congruence theorem using real-life examples and has interesting interactive practice questions.

Learn all about the basic properties of central angles. This lesson targets what is a central angle, central angle formula, central angle calculator, theorem of central angle, how to find central angles, and how to apply them while...

[Free Registration/Login may be required to access all resource tools.] In this lesson students prove two triangles are congruent with the Angle-Side-Angle and Angle-Angle-Side shortcuts. Students examine guided notes, review guided...

Explore quadrilateral properties and threorems.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students the sum of exterior angles for any polygon and the relationship between exterior angles and remote interior angles in a triangle....

Use quadrilateral properties that are unique to parallelograms to prove that the given shape is a parallelogram.

Find out about some common centers of triangles.

See how triangles are congruent where all corresponding angle pairs and sides are the same.

[Free Registration/Login may be required to access all resource tools.] In this lesson students apply the properties of equilateral triangles. Students examine guided notes, review guided practice, watch instructional videos and attempt...

[Free Registration/Login may be required to access all resource tools.] This concept will teach students the properties of equilateral triangles and how to apply them to solve problems. Students examine guided notes, review guided...

[Free Registration/Login may be required to access all resource tools.] In this lesson students compare sides and angles in triangles. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...

A comprehensive guide for learning all about plane shapes with definitions and solved examples.

[Free Registration/Login may be required to access all resource tools.] Use alternate interior angles to determine angle congruency and the presence of parallel lines.