In this mini-lesson, learn about obtuse triangles including the obtuse triangle definition, sides, properties, examples, and other fun facts related to it.

[Free Registration/Login may be required to access all resource tools.] This study guide reviews terminology for triangles, triangle properties, different types of triangles, and interior and exterior angle theorems.

This lesson plan will introduce students to different types of triangles by using a clip from the movie A Walk to Remember. They will take part in interactive tutorials to strengthen the concepts of classifying triangles. The students...

This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.

Use this applet to show how the placement of the third vertex of a triangle affects the classification of that triangle.

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.

Explore full angles triangles with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.

Explore reflex angles triangles with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.

Identify architectural structures and objects in the community that represent different figures and types of geometry and mathematics.

Kindergarteners love to identify shapes in their environment. In order effectively do that, they must be able to recognize different shapes by their specific attributes. In this lesson kindergartners learn about different types of...

[Free Registration/Login may be required to access all resource tools.] This study guide focuses on polygons: convex vs concave, interior and exterior angles, and basic terminology for common polygons.