POLYGONS

Draw a picture of a polygon on each of your post-it notes.

Try to draw two diff erent types of polygons (be creative).

Post them on the front chalkboard (right side)

DRAW AND POST

Take a minute to think about your drawings, what makes a figure a polygon?

Pair up with someone and share your thoughts. (Be sure to listen to their thoughts as well.)

Write down properties you think must exist to call something a polygon.

THINK/PAIR/SHARE

Polygons

Not Polygons

SECTION 6.1WHAT IS A POLYGON? (WRITE

DOWN)

Three or more sides No curved sides Each segment connects to only two others (segments don’t cross)

A POLYGON HAS…(WRITE DOWN)

Aces - come up the board and remove any examples from the board that you think are not polygons and put them on the cabinet.

Twos – Check to see if you agree with the drawings that were removed. Then go to the board and make sure that Row 1 removed all the drawings that should have been removed.

DECIDE AND CHECK

Convex Polygons

CONVEX VS CONCAVE (WRITE DOWN)

Concave Polygons

Convex Polygons

WHAT’S THE DIFFERENCE?

Concave Polygons

Threes– Go to the board and divide the drawings into two groups (Concave/Convex)

Fours – Check to see that the Threes grouped the drawings correctly

DECIDE AND CHECK

If all the angles in a polygon are equal it’s called

If all the sides in a polygon are equal it’s called If a polygon is both equilateral and equiangular it is regular (write down)

equiangular

equilateral

Polygon Names

POLYGON NAMES

Fives – Go to the board and label all the drawings with the appropriate name.

Sixes – Go to the board and check to see if you agree with all of the names

DECIDE AND CHECK

A diagonal connects two non-consecutive vertices (write down)

DIAGONALS

A rectangle has 2 diagonals

Draw the diagonals of a pentagon (5 sides)

DIAGONALS

PENTAGON

In your notes create a table, the size of a full sheet of paper, that has 4 columns and 12 rows. Leave enough room to draw a picture below the name.

TRIANGLES IN A POLYGON

Name # of sides # of triangles

Interior Angle Sum

Triangle 3 1 180

Quadrilateral

….

Dodecagon

n-gonn n - 2 (n – 2) x

180

113+98+42+x=360253+x=360X=107

SOLVE FOR X

90+90+2x+25+3x+5=360 210+5x=360 5x=150 X=30

SOLVE FOR X

What does each interior angle equal in an equiangular 20-gon?

What does each interior angle equal in an equiangular n-gon?

Use this formula to find what each interior angle equals in an equiangular 40-gon.

EQUIANGULAR POLYGONS

First: Name the Polygon.

Second: Determine whether the polygon is convex or concave.

Third: Determine whether the polygon is equilateral, equiangular, regular, or neither.

Fourth: Solve for x.

Pg. 325: 12 – 20, 24 – 34, 37 – 46, 54 - 59

EXIT TICKET HOMEWORK

x x

x x