Angle Sum Property of Triangles

Need worksheets that challenge your middle schoolers to apply their understanding of math? Problem solved! From integers, fractions, and percents, to algebra, geometry, and probability, over 100 pages of word problem worksheets...

Stuck with triangle proofs? Take a 180° and provide learners with a guided worksheet that tests their knowledge with triangle inequalities. The questions require different types of proofs that range in levels of difficulty. 

Use the opposite to organize angles or sides. The video provides the relationship of angle measures based on the lengths of sides in a triangle and its converse. Using two triangles, the segment of a larger playlist on geometry shows the...

This lecture explores the area of each triangle created by drawing two diagonal lines through a rectangle. It provides a detailed explanation of how to use a formula to solve the given problem. Tip: Use this for test preparation purposes.

This lecture explores finding the area of each of the triangles created by drawing two diagonal lines through a rectangle. It provides a detailed explanation of how to use a formula to solve the given problem. Tip: Use this for test...

Take a second look at triangles that are equal all the way around. The video reminds viewers what an equilateral triangle is and points out that the three angles are the same. Using the fact that equilateral triangles are also isosceles,...

Two sides give us two angles. A segment of a playlist on basic geometry revisits isosceles triangles. The presentation explains several properties and theorems related to isosceles triangles.

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.

Determine whether it is right or not. Using the Pythagorean Theorem, the video shows how to determine whether a triangle is a right triangle. Pupils practice the skill in a few of the problems in the associated worksheets on the...

While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...