 ## Presentation on theme: "Polygons and Quadrilaterals"— Presentation transcript:

Polygons The word polygon means “many angles”

What is a Polygon? A closed figure
Made up of three or more straight lines The sides do not cross each other

These are polygons

These are Not Polygons because. . .
Lines are not straight Only two lines Lines Cross Not Closed

A pentagon has five sides.
1 5 2 4 3

Hexagon and Heptagon A hexagon has six sides. (Hexagon and six both have an “x”.) A heptagon has seven sides. heptagon hexagon

Octagon An octagon has eight sides. Count the sides.

Nonagon 9 sides

Decagon Ten Sides

Let’s Review: A pentagon has five sides. A hexagon has six sides.
A heptagon has seven sides. An octagon has eight sides. A nonagon has nine sides A decagon has ten sides

Quadrilaterals parallelogram rectangle trapezoid square rhombus

Definition Quadrilateral – a polygon with 4 angles and 4 straight sides.

Each shape has four sides.
Quadrilaterals “Quad” means four. Why would all of these shapes be called “quadrilaterals”? Each shape has four sides. trapezoid square rhombus parallelogram rectangle

The angles add up to 360º 65º 65º 115º 65º 115º 115º + 65º 115º 360º

Square A square has four sides that are each the same length.
It also has four right angles (perfect corners). 1 4 3 2

Rhombus A rhombus has four sides that are each the same length.
But it has two acute and two obtuse angles. obtuse acute acute obtuse

Square and Rhombus A square and a rhombus both have four sides that are the same length. So, how are they different?

Square and Rhombus A rhombus can be thought of as a slanted square.
If we push on the left-hand side of this square, it might end up looking like… a rhombus.

The only difference between a square and a rhombus is their angles.

Trapezoid A trapezoid has four sides. Two sides are parallel.
The opposing two sides are not parallel. Those are not parallel. Those are parallel.

Rectangle A rectangle has four sides – two long sides and two short sides. Two sides are parallel. The opposing two sides are also parallel. It also has four right angles.

Parallelogram A parallelogram has four sides – two long sides and two short sides. Two sides are parallel. The opposing two sides are also parallel. But, it has two acute and two obtuse angles.

Rectangle and Parallelogram
A parallelogram can be thought of as a slanted rectangle. If we push on the left-hand side of this rectangle, it might end up looking like… a parallelogram.

The only difference between a rectangle and a parallelogram is their angles.

Quadrilaterals SHAPE SIDES ANGLES PARALLEL LINES Square 4 same length
4 right angles 2 sets Rhombus 2 acute 2 obtuse Trapezoid different lengths different angles 1 set Rectangle 2 long, 2 short Parallelogram

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