Students will discover the sum of the interior angles in a triangle using the Cabri Jr. Application.

Determine that all angles in a triangle equal 180 degrees.

This problem provides students with an opportunity to discover algebraic structure in a geometric context. They will divide up polygons into triangles. The will use the sum of the angles of 180 degrees for each triangle. Aligns with...

A short interactive activity to show that the sum of the angles of a triangle is 180 degrees.

In this activity, students learn about the sum of the angles in a triangle. They understand triangles and their interior angles.

This multimedia Learn Alberta math resource looks at angles of a triangle in the context of building bikes and choosing bike sizes. The accompanying interactive component lets students explore build different sized triangles while...

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.

Students construct a line parallel to the base of a triangle and measure the angles formed. They use the construction to prove that the sum of the measures of the interior angles of a triangle is 180 degrees.

[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....

In this task, 8th graders are presented with a drawing of two parallel lines with a triangle touching them at all three of its vertices. They are asked to prove that the sum of the triangles' angles equals 180 degrees. Aligns with 8.G.A.5.

In this activity, students investigate the sum of the measures of the interior angles of a triangle. They will explore interior angles, and their relationship with the exterior angles of a triangle.

This investigation uses Cabri Jr. and a cleaver rotation of a triangle to "prove" that the angles in a triangle add up to 180. This could be used to reinforce triangles and paralled lines as well as introduce the concept of rotating an...

For this task, 8th graders have to reason with angles and angle measurements, including the sum of the angles in a triangle, to deduce information from a picture. Includes a GeoGebra worksheet that the teacher can use for demonstration...

Find missing angle measures using the properties of triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.

Learn what an interior angle of a polygon is and how you can calculate their value in triangles, quadrilaterals, and pentagons. Includes a chart that overviews the "general rule" for determining the sum of internal angles in any polygon...

Find a quick, concise explanation of the Angle Sum Theorem. A step by step explanation of the proof is included to help you understand the theorem.

This site contains a wealth of problems that deal with the basic definitions of medians, altitudes, angle bisectors, and perpendicular bisectors or the defining characteristics of the different types of triangles. There are also...

Explore the world of the angle sum theorem in this mini-lesson. Provides a definition and solved examples that help with understanding their properties. Includes practice questions with answers.

Practice using your graphing calculator for Geometry problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.

In this activity, students investigate the relationship between the exterior angle of a triangle and its remote interior angles. They study the Triangle Sum Theorem and the Exterior Angle Theorem.

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 1 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."

Pythagoras' Theorem: In any right-angled triangle, the square of the length of the hypotenuse (the side that lies opposite the right angle) is equal to the sum of the squares of the other two sides. (A+B=C)

Given information in a geometric context, students will be able to use informal arguments to establish facts about the angle sum and exterior angle of triangles, the angles created when parallel lines are cut by a transversal, and the...