Texas Education Agency
Texas Gateway: Geometric Properties of Angle Relationships in Polygons
Given numerical and/or geometric patterns that represent geometric properties of angle relationships in polygons, the student will investigate patterns to make conjectures about interior and exterior angles of polygons.
Texas Instruments
Texas Instruments: Measuring Polygons an Introduction to Cabri Jr.
This activity is designed as an introduction to using the Carbri Jr. application on the TI-83+/84+ calculators. Students are guided through the menu system and are shown how to draw triangles, quadrilaterals and and a pentagon. Perimeter...
Oswego City School District
Regents Exam Prep Center: Polygons: Interior and Exterior Angles
A great resource where you can learn how to calculate the measures of the interior and exterior angles of any regular polygon with these tutorials. There are several practice pages for someone to try. The teacher resource page includes...
Sophia Learning
Sophia: Sum of Angles in Polygons
This tutorial with video and slideshow components investigate the characteristics of polygons as well as how to calculate the interior and exterior angles of any polygon. It offers two PowerPoint presentations and two videos that feature...
Texas Education Agency
Texas Gateway: Making Conjectures About Other Polygons
Given information about the properties of polygons, students will verify theorems about the relationships, including the sum of interior angles, and apply these relationships to solve problems.
CK-12 Foundation
Ck 12: Geometry: Exterior Angles in Convex Polygons
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate exterior angles of regular polygons. Students examine guided notes, review guided practice, watch instructional videos...
CK-12 Foundation
Ck 12: Geometry: Exterior Angles in Convex Polygons
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the measure of the exterior angles of a polygon. Students examine guided notes, review guided practice, watch instructional videos and...
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles in Parallelograms
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine missing angles in a parallelogram.
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles in Trapezoids
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on finding the missing angles in a trapezoid.
CK-12 Foundation
Ck 12: Geometry: Exterior Angles Theorems
[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....
OER Commons
Oer Commons: Exploring Polygons
For this lesson, students explore different polygons by drawing them, measuring angles, and manipulating interactive sketches to find the angle sum for any polygon. Students also explore the angle measures in regular polygons. Included...
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.
CK-12 Foundation
Ck 12: Geometry: Interior Angles in Convex Polygons
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the sum of the interior angles of a polygon and the measure of one interior angle of a regular polygon.
Math Is Fun
Math Is Fun: Interior Angles of Polygons
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...
Illustrative Mathematics
Illustrative Mathematics: A ced.a.1: Sum of Angles in a Polygon
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...
Khan Academy
Khan Academy: Angles of a Polygon
Find the sum of interior angles of different polygons.
Texas Instruments
Texas Instruments: Angles in a Polygon
Students will expore the interior and exterior angle of 3 polygons and develop the formula to calculate the sum of degrees without the measurement of the angles being taken.
Math Open Reference
Math Open Reference: Interior Angles of a Polygon
Learn about interior angles of a polygon with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Mangahigh
Mangahigh: Shape: Exterior Angles of Polygons
Explain that the sum of exterior angles of polygons equal 360 degrees.
Mangahigh
Mangahigh: Shape: Interior Angles of Polygons
Determine the sum of the interior angles of polygons.
Texas Instruments
Texas Instruments: Triangle Sum
This activity is used to discover that the sum of the measures of the triangle angles is constant and to discover ways of proving the theorem listed in the activity.
AAA Math
Aaa Math: Finding the Third Angle of a Triangle
Finding the third angle of a triangle becomes easier by the explanation and examples presented.
CK-12 Foundation
Ck 12: Geometry: Interior Angles in Convex Polygons
[Free Registration/Login may be required to access all resource tools.] Find the sum of the interior angles of a convex polygon.
Mathigon
Mathigon: Geometry: Angles and Polygons: Drawing Triangles
This lesson focuses on the Triangle Inequality, when the sum of the lengths of any two sides of a triangle is greater than the length of the third. When this happens, the three sides cannot form a triangle.