[Free Registration/Login may be required to access all resource tools.] Apply the special properties of 30-60-90 right triangles.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students about the 30-60-90 special right triangle and how to apply its properties.

Explains the basic concept of lines and angles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Discovering the properties of constructions, seeing proofs in action, and viewing problems come to life here with this wonderful use of technology in the classroom. Single steps are explained and illustrated one at a time so that the...

Explains the basic concept of chords with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Explains the basic concept of arcs, angles, and sectors with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Explains the basic concept of congruent triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

The University of St. Andrews offers a brief history of the first math problem to be solved with computers.

This lesson focuses on triangle congruence; it shows the ways to prove that triangles are congruent.

Explains the basic concept of triangle inequalities with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Explains the basic concept of similar triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Explains the basic concept of circles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Explains the basic concept of trapezoids with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

Contains a detailed biography and discussion of the contributions of the ancient Greek philosopher Thales. Part of a larger mathematics site, this page focuses primarily on his contributions to Geometry.

Explore different ways of proving some theorems about lines and angles. Some transformations are used. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.

Students learn about the unit circle. Topics include degrees, radians, and Pythagoras' Theorem. The tutorial consists of notes and examples.

View and learn about five different polyhedra: tetrahedron, octahedron, icosahedron, hexahedron, and dodecahedron. Learn what Euler's Polyhedra Theorem is, and see examples of non-polyhedra as well.

In this activity, students will learn that math is important in navigation and engineering. Ancient land and sea navigators started with the most basic of navigation equations (Speed x Time = Distance). Today, navigational satellites use...

Each calculation option has sub-bullets that list the sequence of methods used in this calculator to solve for unknown angle and side values including Sum of Angles in a Triangle, Law of Sines, and Law of Cosines.

In Spanish. Different activities which involve the following concepts: right triangles, perpendicular lines, classification of triangles, area of a square and Pythagorean theorem.

This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.

Here is a math problem using a football field as its basis. The solution to the problem involves the Pythagorean theorem.

[Free Registration/Login may be required to access all resource tools.] Find the length of sides of right triangles using the Pythagorean Theorem.

Use the Pythagorean Theorem to determine if the given side lengths could form a right triangle, i.e., which set forms a Pythagorean triple. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a...