# Triangle Inequality

##### This Triangle Inequality lesson plan also includes:

This STEM lesson plan presents a guided inquiry-based activity on exploring the relationship between the side lengths of a triangle. Class members are encouraged to also find the relationship between angle measure and side lengths. Notes, a pre- and post assessment, homework, and an exit ticket offer the teacher support in covering the concept.

##### Instructional Ideas

• Have the class determine an algebraic rule to quickly determine whether a triangle can be formed from any given side lengths
• Spend as much time investigating the relationship between the side lengths and angle sizes as the side inequality relationship
##### Classroom Considerations

• An extensive list of supplies is needed that includes uncooked spaghetti and/or straws
• Student familiarity with collaborative group roles would be beneficial
##### Pros

• Data notes chart provided to assist with formative assessment
• Pre-assessment is designed to determine prerequisite skills for the activity
##### Cons

• The Hinge Theorem relationship is treated as an after-thought or only as an extension
• Answers are not provided for the assessments