Triangle Inequality Theorem Lesson Plan (7th grade)

Lesson Plan

                               

Subject/Topic: Math/ Triangle Inequality Theorem

Time (minutes) required for lesson: 60 minutes                             

CC Georgia Performance Standards for this lesson:

MCC7.G.2. Draw (freehand, with ruler and protractor, and with technology) geometric shapes with given conditions. Focus on constructing triangles from three measures of angles or sides, noticing when the conditions determine a unique triangle, more than one triangle, or no triangle.

Essential Question(s):

• What is the relationship between the sides of a triangle?

 Purpose/Relevance:

• Students need to understand what side lengths will create a triangle in order to recognize whether measurements are valid or not.

Goals of lesson aligned with CC Georgia Performance Standards:

• Students will be able to determine whether side lengths create a triangle by applying their understanding of the triangle inequality theorem. 
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• Materials/Equipment/Technology Required:

• Computer, projector, and Mobi Tablet OR white board.
• Olympic Math website: http://nrich.maths.org/8191
• Straws and Triangle Inequality Theorem worksheet

PROCEDURES

Warm-up: (10 minutes)

Olympic Math- Identify and describe angles various pictures from the Olympics which highlight angle relationships such as supplementary, complementary, vertical, corresponding, and adjacent.

Format of the lesson: (30 minutes)

Independent Practice:

1.     Students will work individually to create various examples of triangles using the manipulative activity and discover the pattern that lends itself to the Triangle Inequality Theorem. The teacher will facilitate learning by keeping students on track and answering any questions they may have, but the students will discover the theorem for themselves.  

Direct Instruction: (10 minutes)

1.      Teacher will take examples from each student and use probing questions to draw out the pattern that the students found from their experimentation.

Closure: 10 minutes

1.      Ask students to summarize what they learned. 

2.      Exit ticket. Using the formula for the Triangle Inequality Theorem, give one example of a set of sides that do not create a triangle and another example of a set of sides that do create a triangle.

Appendices:

Triangle Inequality Theorem Task http://www.glencoe.com/sites/common_assets/support_pages/MC_Course3/Triangle_Inequality.pdf