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Big Ideas:
Triangles cannot be formed given any three sides.
When given three side lengths to form a triangle, the sum of two lengths of the triangle must be larger than the other side.
Students will be building on their knowledge of triangle construction. The focus of this lesson is for students to prove that a triangle cannot be formed given any three random sides. By the end of the lesson, students will understand that when given three lengths to create a triangle, the sum of two sides must be greater than that of the other side. If the side is not greater, a triangle cannot be formed.
Vocabulary: Triangle Inequality Theorem, acute, obtuse, right, scalene, isosceles, and equilateral triangles
Special Materials:
Rulers and straws