Exploring Polygons What is a polygon Polygons are

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Exploring Polygons

Exploring Polygons

What is a polygon? Polygons are many-sided figures, with sides that are line segments.

What is a polygon? Polygons are many-sided figures, with sides that are line segments. Polygons are named according to the number of sides and angles they have.

Polygon or NOT?

Polygon or NOT?

Polygon or NOT?

Polygon or NOT?

Regular or Irregular? Can be “regular” – all sides and all angles are equal

Regular or Irregular? Can be “regular” – all sides and all angles are equal to each other. Regular or irregular?

Can you make a 2 -sided polygon? Try to draw it in your notebook.

Can you make a 2 -sided polygon? Try to draw it in your notebook. Talk and Turn to discover whether this is possible or not. Why or why not?

What are 3 -sided polygons called? TRIANGLES!

What are 3 -sided polygons called? TRIANGLES!

Isosceles Triangles Two sides of equal length Three acute angles Sum of angles =

Isosceles Triangles Two sides of equal length Three acute angles Sum of angles = 180°

Isosceles Chant! Teacher: Students: Isosceles! 2 sides equal! When I say, isosceles, you say

Isosceles Chant! Teacher: Students: Isosceles! 2 sides equal! When I say, isosceles, you say 2 sides equal!

Equilateral Triangles All sides equal length Three acute angles Sum of angles = 180°

Equilateral Triangles All sides equal length Three acute angles Sum of angles = 180° Is a regular polygon

Equilateral Chant! Teacher: Students: Equilateral! all sides equal! When I say, equilateral, you say

Equilateral Chant! Teacher: Students: Equilateral! all sides equal! When I say, equilateral, you say all sides equal!

Scalene Triangles No sides are equal No angles are equal May have obtuse angle

Scalene Triangles No sides are equal No angles are equal May have obtuse angle Sum of angles = 180 °

Scalene Chant! Teacher: Students: Scalene! NO sides equal! When I say, scalene, you say

Scalene Chant! Teacher: Students: Scalene! NO sides equal! When I say, scalene, you say NO sides equal!

Another way to classify triangles! By their angles!!

Another way to classify triangles! By their angles!!

Right Triangle Has 1 right angle! 90 degrees The little square box in the

Right Triangle Has 1 right angle! 90 degrees The little square box in the corner

Talk and Turn: Can you make a triangle with 2 right angles? Why or

Talk and Turn: Can you make a triangle with 2 right angles? Why or why not?

Acute Triangle with all angles LESS than 90 degrees. The curve shows that it

Acute Triangle with all angles LESS than 90 degrees. The curve shows that it is an acute angle. ALL triangles have some acute angles. An acute triangle is special, because it has ALL acute angles.

Obtuse Triangle: A triangle with one obtuse angle (more than 90 degrees) Talk and

Obtuse Triangle: A triangle with one obtuse angle (more than 90 degrees) Talk and Turn: can you make a triangle with more than one obtuse angle? Why or why not?

What do you call a 4 -sided polygon? 4 sides 4 angles QUAD =

What do you call a 4 -sided polygon? 4 sides 4 angles QUAD = 4

Quadrilateral Classification There are many types of SPECIAL quadrilaterals

Quadrilateral Classification There are many types of SPECIAL quadrilaterals

Rectangles Opposite sides are parallel Opposite side are equal in length Each angle equals

Rectangles Opposite sides are parallel Opposite side are equal in length Each angle equals 90° Sum of angles = 360°

Squares All sides equal All angles equal and are 90 ° each Sum of

Squares All sides equal All angles equal and are 90 ° each Sum of angles = 360 ° Is a regular polygon

Trapezoids Two sides are parallel Has obtuse and acute angles Sometimes has a right

Trapezoids Two sides are parallel Has obtuse and acute angles Sometimes has a right angle Sum of angles = 360 °

Rhombuses (rhombi) All four sides of equal length Opposite angles are equal – 2

Rhombuses (rhombi) All four sides of equal length Opposite angles are equal – 2 acute angles, 2 obtuse angles Sum of angles = 360 ° Regular polygon

Parallelograms Opposite sides parallel Opposite sides equal in length Opposite angles equal Sum of

Parallelograms Opposite sides parallel Opposite sides equal in length Opposite angles equal Sum of angles = 360 °

“Just a Boring Square” http: //www. schooltube . com/video/2020 fa 2 f 64 2304

“Just a Boring Square” http: //www. schooltube . com/video/2020 fa 2 f 64 2304 cf 32 e 4/Polygon. Song

Pentagons 5 sides Sum of angles = 540 ° Regular polygon

Pentagons 5 sides Sum of angles = 540 ° Regular polygon

Hexagons 6 sides Sum of angles = 720 ° Can be regular polygon

Hexagons 6 sides Sum of angles = 720 ° Can be regular polygon

Octagons 8 sides Sum of angles = 1080 ° Can be regular polygon

Octagons 8 sides Sum of angles = 1080 ° Can be regular polygon

Nonagon 9 sided polygon 9 angles

Nonagon 9 sided polygon 9 angles

Decagons 10 sides Sum of angles = 1440° Can be regular polygon

Decagons 10 sides Sum of angles = 1440° Can be regular polygon