# day 4 - Carl Schurz High School Bell Ringer 9/13 How many diagonals can be formed in a 13 sided polygon? (n)(n-3) 2

(13)(10) = 65 2 Geome try Goals Today

What does invariant mean? invariant is something that does not - Finding patterns change under a set of transformations.

- Making generalizations so something that stays constant. from concrete examples - Identifying invariants Discovering the Inequality TheoremInequality Inequality TheoremTheorem 1)Form a triangle with 4 in.

5 in. & 8 in. straws. Is it possible? 2) Copy the data sheet into your notes 3) Try the following lengths from the data sheet and fill in the table. 4) Answer the two questions from the data sheet into your notes. Get ready

for.. 3 pieces does not form a triangle 3 pieces do form a triangle Can we generalize

anything here about the lengths of the sides of a triangle Lets discuss Get to the point Go ahead and summarize what you have discovered. (One or two sentences)

The sum of any two sides of a triangle must be greater than the length of the third side. Triangle Inequality Practice Problems Class / Homework .. On your paper

Copy this chart & find me three different examples which have sides lengths that form a triangle. Use a ruler to measure each straw length. (You may need to trade straw pieces with a partner to have enough different sized pieces). Continue on your paper Now find me three different examples which

have sides lengths that DO NOT form a triangle.