Exploring

Figures can be identified, described, compared and classified in different ways.

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

Can be “regular” – all sides and all angles are equal to each other

Two sides of equal length

Three acute angles Sum of angles =

180°

All sides equal length

Three acute angles Sum of angles =

180° Is a regular

polygon

No sides are equal No angles are

equal May have obtuse

angle Sum of angles =

180 °

Opposite sides are parallel

Opposite side are equal in length

Each angle equals 90°

Sum of angles = 360°

All sides equal All angles equal

and are 90 ° each Sum of angles =

360 ° Is a regular

polygon

Two sides are parallel

Has obtuse and acute angles

Sometimes has a right angle

Sum of angles = 360 °

All four sides of equal length

Opposite angles are equal – 2 acute angles, 2 obtuse angles

Sum of angles = 360 °

Can be a regular polygon

Opposite sides parallel

Opposite sides equal in length

Opposite angles equal

Sum of angles = 360 °

5 sides Sum of angles =

540 ° Regular polygon

6 sides Sum of angles =

720 ° Can be regular

polygon

8 sides Sum of angles =

1080 ° Can be regular

polygon

10 sides Sum of angles =

1440° Can be regular

polygon

Regular Irregular Triangle Acute Angle

Quadrilateral Pentagons Hexagons Right angle

Parallel sides Equal sides Reflex angle Obtuse angle

Convex polygon

Concave polygon

Each of these polygons has all angles less than 180 degrees. These are convex polygons

Each of these polygons has at least one reflex angle (greater than 180 degrees). These are concave polygons.

Regular Irregular Triangle Acute Angle

Quadrilateral Pentagons Hexagons Right angle

Parallel sides Equal sides Reflex angle Obtuse angle

Convex polygon

Concave polygon

Regular Irregular Triangle Acute Angle

Quadrilateral Pentagons Hexagons Right angle

Parallel sides Equal sides Reflex angle Obtuse angle

Convex polygon

Concave polygon

1.Read pages 86-872.Complete q’s 1, 2 on pg 88.