Texas Instruments
Texas Instruments: Properties of the Centers of a Triangle
Students investigate the sum of the measures of the interior angles of a triangle. This activity explores interior angles, and their relationship with the exterior angles of a triangle [Requires Adobe Reader.]
ClassFlow
Class Flow: Linear Pair and Vertical Angle Discoveries
[Free Registration/Login Required] In this Flipchart, students explore linear pairs and vertical angles. Students determine the measure of interior and exterior angles.
ClassFlow
Class Flow: Parallel Lines and Angle Relationships
[Free Registration/Login Required] Explore the relationships between parallel lines and the rules of angle measurements.
PBS
Pbs Learning Media: Directions to Hen Rock
The CyberSquad has to deal with angles and distances to locate a treasure chest in this video segment from Cyberchase.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.3 Polygons
Explore the structure and measurement of polygons.
ClassFlow
Class Flow: Classifying Triangles
[Free Registration/Login Required] This lesson covers methods of classifying triangles, both according to the length of their sides and by the measure of their interior angle.
Illustrative Mathematics
Illustrative Mathematics: G Mg, a Ced Regular Tessellations of the Plane
This task examines the ways in which a plane can be covered by regular polygons in a regular tessellation arrangement. The problem uses the formula for the measure of the interior angles of a regular polygon and the goal of the task is...
Illustrative Mathematics
Illustrative Mathematics: 8.g Tile Patterns I: Octagons and Squares
Eighth graders are presented with a tile pattern showing an apparent square surrounded by four octagons. They are asked to answer a question about congruency and angle measurements, as well as prove that the interior shape is really a...