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.
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...
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.
Khan Academy
Khan Academy: Angles of a Polygon
Find the sum of interior angles of different polygons.
Texas Instruments
Texas Instruments: Investigating the Angle Sum Theorem of Polygons
This activity will allow students to use Cabri Jr. to find the sum of the measures of interior angles of convex polygons and visually see how the Interior Angle Sum Theorem works.
Mangahigh
Mangahigh: Shape: Exterior Angles of Polygons
Explain that the sum of exterior angles of polygons equal 360 degrees.
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...
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.
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: 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.
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: 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....
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.
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.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles: Lesson 1
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."
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: Exterior Angles of Polygons
This site explains what the measure of the sum of exterior angles is for any polygon, and shows how to find the measure of individual exterior angles for regular polygons with a drawn example.
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.
Varsity Tutors
Varsity Tutors: Hotmath: Exterior Angles
This interactive tool has student explore the topic of exterior angles of a polygon. The tool allows learners to change the number of sides to find the sum of the exterior angles of a variety of polygons.
Cuemath
Cuemath: Angle Sum Theorem
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.
ClassFlow
Class Flow: Investigating Regular Polygons
[Free Registration/Login Required] In this lesson students are introduced to regular polygons. Students learn how to find the drawing angle of any given polygon, exterior angle, interior angle and the sum of the angles for a regular...
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.