# Go over quiz.

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Go over quiz

3.4 Polygon Angle Sum Theorems
10/28 with practice on 10/29

Learning Targets I can name and classify a polygon given the number of sides and vertices. I can find the interior angles of a polygon using the Polygon Angle Sum Theorem I can find the exterior angle of a polygon using the Polygon Exterior Angle Sum Theorem

Polygon : a polygon is a closed plane figure with at least three sides that are segments. The sides intersect only at their endpoints.

To name a polygon, you must name the vertices consecutively
EX:

Convex polygon: Has no diagonals with points outside the polygon.
Concave polygon: Has at least one diagonal with points outside the polygon. EX

Part a is Convex part b is Concave

Polygon Classification
3 sides- 4 sides- 5 sides- 6 sides-

Polygon Classification(cont’d)
7 sides - 8 sides - 9 sides - 10 sides - 12 sides - N sides -

Polygon Angle Sum Theorem: The sum of the measures of the interior angles of any polygon is (n – 2)180, where n is the number of sides.

Ex. What is the sum of the measures of angles of a Decagon? Pentagon?

Find the sum of the measures of angles of an octagon
In your groups Find the sum of the measures of angles of an octagon

Find x

In your groups The sum of the measures of the interior angles is How many sides does it have? Hint: Work backwards

Polygon Exterior Angle Sum Theorem: The sum of the exterior angles of a polygon is 360 degrees. ALWAYS!

The following is SUPER IMPORTANT!!!
An Equilateral polygon has all sides congruent. An Equiangular polygon has all angles congruent. The following is SUPER IMPORTANT!!! A regular polygon has all equal angles and equal sides.

In your groups What is the measure of an exterior angle of a regular hexagon? What is the measure of an interior angle of a regular dodecagon?

In your groups The following is a regular polygon, find the missing measures

In a regular polygon, the sum of an interior angle and exterior angle is 180°

Homework In packet 3-4

Day 2 for 3.4 Warmup – Grab your book For a regular nonagon
What is the measure of an interior angle? What is the measure on an exterior angle?

Go over 3-4 Packet.

P.147 #16-21

3-4 worksheet practice