2.4 - Quadrilateral Classification

1) Review: Tools you'll need to classify a Triangle given 3 side lengths.

• Determining if 3 numbers are possible side lengths of a triangle: Triangle Inequality Theorem

• Determining if a triangle is equilateral, isosceles, or scalene is done by definition.
• Equilateral triangles have 3 congruent sides. 
• You need to test to make sure all sides are equal. This Boolean (filled in correctly of course) should do the trick.
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• Question: Why don't you need a 3rd equality check in this case?
• Isosceles triangles have only 1 pair of congruent sides. This Boolean should be helpful. 
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• If a triangle is not Equilateral or Isosceles, this means it is scalene. None of the sides have equal lengths. 

• Determining if a triangle is right, acute, or obtuse is easily tested by the converses of the Pythagorean theorem.  
  

2) Short Lesson: Quadrilateral family tree.

2) You should work on completing any elements of 2.3 that are not done yet.

3) When you are done, begin Lab 2.4 Classifying Quadrilaterals.