Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders discover the patterns of sums of polygon angles. In this math lesson plan, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Polygons
Get independent practice working with polygons and their characteristics. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles in Composite Figures
[Free Registration/Login may be required to access all resource tools.] Students watch a video and take an assessment on finding missing angles in a polygon.
National Council of Teachers of Mathematics
Nctm: Illuminations: Angle Sums
Students may use this computer applet to explore angle sums of triangle, quadrilaterals, pentagons and hexagons.
Free Math Help
Free Math Help: Interior Angles of a Polygon
The Geometry tutorial discusses interior and exterior angles of a polygon. Sample exercises with explanations are included.