CK-12 Foundation
Ck 12: Geometry: Relation of Polygon Sides to Angles and Diagonals
[Free Registration/Login may be required to access all resource tools.] Find interior angle measures of polygons by drawing diagonals to create triangles.
Khan Academy
Khan Academy: Quadrilateral Angles
Find missing angle measures in quadrilaterals. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
OER Commons
Oer Commons: Exploring Polygons
In this lesson, young scholars 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....
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...
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.
Mangahigh
Mangahigh: Shape: Quadrilaterals Inscribed in Circles
Determine the missing angle measures of quadrilaterals inscribed in circles.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Similarity
This site contains a lesson plan for high school age students. The objective is to discover the factor of proportionality in similar polygons and to relate this factor to the perimeters and areas of similar polygons.
OER Commons
Oer Commons: Classifying Triangles
In this lesson, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included are...
CK-12 Foundation
Ck 12: Geometry: Congruent Figures
[Free Registration/Login may be required to access all resource tools.] In this tutorial, students recognize congruence and find unknown measures of angles. They can examine guided notes, review guided practice, watch instructional...
National Council of Teachers of Mathematics
Nctm: Figure This: Windshield Wipers
Test your mathematical aptitude with challenge exploring the concepts of measurement and geometry. Find the area of the windshield wipers to figure out who sees better in the rain, car drivers or truck drivers. An activity from the NCTM...
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...
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.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Geometry
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.