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.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice: Polygons and Area of Plane Figures
Practice using your graphing calculator for measuring and constructing polygons and other plane figures. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under...
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.
University of Regina (Canada)
University of Regina: Math Central: Interior Angle Measure of a Polygon
This is a question response page from the University of Regina where one may find an algorithm for finding the number of degrees of any convex polygon.
University of Regina (Canada)
University of Regina: Math Central: Interior Angle Measure of a Polygon
This is a question response page from the University of Regina where you will find an algorithm for finding the number of degrees of any convex polygon.
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.
AAA Math
Aaa Math: Finding the Fourth Angle of a Quadrilateral
An interactive site that instructs and demonstrates how to find the fourth angle of a quadrilateral. This site also has many links to other interactive lessons.
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...
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
University of Regina (Canada)
University of Regina: Math Central: Interior Angle Measure of a Polygon
This is a question response page from the University of Regina where you will find an algorithm for finding the number of degrees of any convex polygon.
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...
OER Commons
Oer Commons: Pre Assessment
Students solve for missing angle measures by applying what they have learned about types of angles and the angle measures of polygons. Students do a pre-assessment at the end of the lesson.
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.
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.
Math Open Reference
Math Open Reference: Constructions
Learn about drawing shapes using only a compass and straight edge or ruler with out measuring any lengths or angles.
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...
Mangahigh
Mangahigh: Shape: Quadrilaterals Inscribed in Circles
Determine the missing angle measures of quadrilaterals inscribed in circles.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.5 Quadrilaterals
Explore and measure a variety of quadrilaterals.
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.
CK-12 Foundation
Ck 12: Isosceles Triangles
[Free Registration/Login Required] Students are given an Isosceles triangle and are asked to move the point on the line segment to explore how the angle measure changes. Click learn more to watch a video demonstration and click challenge...
Math Slice
Math Slice: Geometry Slice Special Test
A succinct test for assessing geometry concepts. Assessment is scored online giving immediate feedback. An excellent assessment tool.