Polygon Information

Triangle InformationConsider this pattern: 30+60+90=18045+45+90=18040+50+90=18010+80+90=180 Based on this, what can you say about the acute angles in a right triangle?

Try it! Make a conjecture about the angles

in an equiangular triangle.

Triangle TheoremIf 2 angles of one triangle are congruent to 2 angles of another triangle, then make a conjecture about the 3rd angle.

Congruent Polygons

Polygon Vocabulary

Regular Polygons

Not Regular Polygons

Make a conjecture about regular polygons

Convex Concave

Number of Sides

Name of Polygon

4 Quadrilateral5 Pentagon6 Hexagon7 Heptagon8 Octagon9 Nonagon10 Decagon12 Dodecagonn N-gon

Polygon TheoremsNumber of sides

Number of triangles created by diagonals

Sum of interior angles

Measure of one interior angle

3 14 25678n (____)

FIND THE TREND!Number of sides

Measure of one Interior angle

Measure of one exterior angles

Sum of exterior angles

3 60 1204 905 1086 12010 14420 162n Doesn’t

matter

ExamplesIn ABC, and . Find the .

Based on the figure, write a conjecture about ADB and CBD.

ExamplesWrite a conjecture given the figure below. R is the midpoint of .

ExamplesGiven that the interior angles and exterior angles of a regular polygon are congruent, what is the name of the polygon.