Warm-Up: Copy and Complete The last day to turn in ANY late or missing work is ______________________. All test re-takes must be taken ________________.

Warm-Up: Copy and Warm-Up: Copy and CompleteComplete

• The last day to turn in ANY late or missing work is ______________________.

• All test re-takes must be taken ________________ or during PACK this week.

• Define Quadrilateral

Polygon Polygon classificationclassification

Concave Polygon Convex Polygon

1.

Homework: p 386 #1-15, 23-33 odd

Classifying Classifying PolygonsPolygons

2. Naming Polygons based on the number of sides:

3 sides =

4 sides =

5 sides =

6 sides =

7 sides =

8 sides =

9 sides =

10 sides =

Triangle (This label is based on the number of angles.)

Quadrilateral

Pentagon

Hexagon

Heptagon

Octagon

Nonagon

Decagon

PolygonsPolygonsTriangle - A polygon with three sides.

PolygonsPolygonsQuadrilateral - A polygon with four

sides.

PolygonsPolygonsParallelogram - A quadrilateral with

two pairs of parallel sides.

PolygonsPolygonsTrapezoid - A quadrilateral which has

one pair of parallel sides.

PolygonsPolygonsRectangle - a quadrilateral with four

congruent angles (all 90°).

PolygonsPolygonsRhombus - A parallelogram with four

congruent sides.

PolygonsPolygonsSquare - a quadrilateral with four

congruent sides and four congruent angles (all 90°).

PolygonsPolygonsPentagon - A polygon with five sides.

PolygonsPolygonsHexagon - A polygon with six sides.

PolygonsPolygonsOctagon - A polygon with eight sides.

PolygonsPolygonsDecagon - A polygon with ten sides.

Bell W

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5 minutes

3. How do you find the sum of the interior angles of an n-gon?

)2(180 nSum of Interio

r Angles

Polygon Polygon PracticePractice

3. Find the sum of the interior angles of the following polygons.Hexagon: 22-gon

)2(180 nSum of Interior Angles

Hexagon

Sum of Interior Angles

)26(180 Sum of Interior Angles

4180

Sum of Interior Angles

720

)2(180 nSum of Interior Angles

22-gon

Sum of Interior Angles

)222(180 Sum of Interior Angles

20180

Sum of Interior Angles

3600

Polygon Polygon practicepractice

3. What does “sum of the interior angles” mean?

The answer when I add up all of the angles on the INSIDE of a polygon.

Polygon Polygon practicepractice

4. What is a regular polygon?

All of the angles are the congruent (same measure) and all of the sides are congruent (same length).

Polygon Polygon practicepractice

3. How do you find the measure of an (each/one) interior angle of a regular n-gon?

n

n )2(180

Measure of One Interior

angle of a Regular n-

gon

Polygon Polygon practicepractice

3. Find the measure of each interior angle of the following polygons.Hexagon: Nonagon

n

n )2(180 Measure of

one Interior Angle

Hexagon

Measure of one Interior

Angle6

)26(180

Measure of one Interior

Angle6

4180

Measure of one Interior

Angle6

720

Measure of one Interior

Angle

120

n

n )2(180 Measure of

one Interior AngleMeasure of

one Interior Angle

9

)29(180

Measure of one Interior

Angle9

7180

Measure of one Interior

Angle9

1260

Measure of one Interior

Angle

140

Nonagon

Polygon Polygon practicepractice

4. What is the sum of the exterior angles of any regular polygon?

The sum of the measures of the exterior angles of any polygon is always .

360

Polygon Polygon practicepractice

4. How do you find the measure of one exterior angle of a regular polygon?

n

360Measure of

One Exterior angle of a Regular n-

gon

Polygon Polygon practicepractice

6. Find the measure of an exterior angle of the following regular polygons.

n

360Measure of

one Exterior Angle

Decagon

Measure of one Exterior

Angle10

360

Measure of one Exterior

AngleMeasure of one Exterior

Angle

Pentagon

Measure of one Exterior

Angle

36Measure of one Exterior

Angle

n

360

5

360

72

Polygon Polygon practicepractice

7. Find the number of sides for a regular polygon using the information given:

a)The measure of each exterior angle is 30 degrees.

30

360

n

nn

n

30360

n

30

360

n10

Polygon Polygon practicepractice

7. Find the number of sides for a regular polygon using the information given:

b) The measure of each interior angle is 135 degrees.

135

180)2(

n

n

Polygon Polygon practicepractice

7. Find the number of sides for a regular polygon using the information given:

a)The measure of each exterior angle is 30 degrees.

b)The measure of each interior angle is 135 degrees.

30

360

n

30

360

n

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End

Quiz PracticeQuiz Practice1) Find “x” and “y”. 2) Find each angle

A little more practiceA little more practice• 3) Find a, b and c.

30

ab

c

Exit TicketExit Ticket1. Name the polygon by the number of its sides.

Then tell whether the polygon is regular or irregular, concave or convex.

1. Find the sum of the interior angle measures of a convex 11-gon.

2. Find the measure of each interior angle of a regular 18-gon.

3. Find the measure of each exterior angle of a regular 15-gon