Isosceles Triangle Theorem

Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...

Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...

The measures all add up. The presentation, part of a helpful playlist on geometry, provides the statement of the Triangle Sum Theorem. Using the theorem, the video shows how to find the missing measure of an angle.

Can any three lengths make a triangle? One of the videos in a playlist on basic geometry introduces the Triangle Inequality Theorem. Using three given lengths, the presentation illustrates the restrictions on lengths of any side of a...

Look at proportionality from a parallel perspective. A section of an expansive geometry playlist introduces the Triangle Proportionality Theorem. Using the theorem, the video shows how to determine missing measurements in triangles.

If you add the value of the three interior angles in a triangle will it equal 180 degrees? Yes it will. The instructor illustrates and proves the Triangle Sum Theorem. Follow closely as she explains her proof.

Are you working on finding the missing angles of triangles in your class? Consider this video. An instructor uses the triangle sum theorem to create an equation that helps her find the missing angles. She explains each step and writes...

Are you working on finding the missing angles in triangles in your class? Consider this video. An instructor uses the triangle sum theorem to create an equation that helps her find the missing angles. She explains each step and writes...

Learn how to identify an equilateral triangle by evaluating its congruent sides. Once you've determined that that sides are congruent you'll be able to use the triangle sum theorem to determine the angles in an equilateral triangle. This...

Don't believe everything that you hear — make them prove it! The video shows two methods to prove the Triangle Angle Sum Theorem. The following two videos apply the theorem to finding missing angle measures.