Explore the world of acute triangles in this mini-lesson. Explores its properties, how to create it, and other interesting facts related to acute triangles.

[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to classify triangles based on angle measures.

On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...

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.

A list of geometry definitions and a matching activity.

This site has an activity that displays several impossible triangles. The rules for triangles are also displayed. The student has to determine which rule has been violated for each impossible triangle.

Given the side lengths of a right triangle, find the sine, cosine, or tangent of one of the acute angles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to determine if triangles are acute, obtuse, or right triangles.

[Free Registration/Login may be required to access all resource tools.] Classify triangles by side lengths and angle measures.

[Free Registration/Login may be required to access all resource tools.] Classify triangles by side lengths and angle measures.

[Free Registration/Login may be required to access all resource tools.] Classifying triangles by using angle measures and side lengths.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to classify triangles based on their angles and sides.

[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.

Given one side length and an acute angle in a right triangle, find another side using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

This Oswego City School District site from the Regents Exam Prep Center provides an explanation of the classifications of triangles both by sides and by angles. Pictures are also included.

[Free Registration/Login may be required to access all resource tools.] Find the degree measure of an unknown angle in given triangles.

This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.

Given two sides in a right triangle, find one of the acute angles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Practice finding the area of right, acute, and obtuse triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

[Free Registration/Login may be required to access all resource tools.] This concept introduces students to several applications of the Pythagorean Theorem. Students examine guided notes, review guided practice, watch instructional...

Students explore four types of angles in this interactive web lesson.

Do you need practice remembering or learning different geometry vocabulary words and definitions? This word search is the web site for you! There is a link to a list of terms with definitions you can click if you want to see if you are...

This site provides definitions of different types of polygons and figures.