What is a “polygon”? =a closed shape with straight line segments

Mystery Sort Activity:

1) What shapes do you see in: Set 1 =

Set 2 =

Set 3 =

2) What do all the shapes in Set 1 have in common?

3) What do you notice about the sides of the shapes in sides Set 2?

square, triangle, hexagon

Rectangle, triangle, pentagonparallelogram

triangle, octagon, rhombus,pentagon

All sides and angles are equal

Each shape has at least 2 sides of different lengths. No shape has all sides equal.

4) What do you notice about the angles in the shapes in Set 2?c

The rectangle has all angles equal. The other 3 shapes do not.

5) What kind of triangle is in Set 3?

6) Does it share any attributes with the shapes in Set 1?

7) Describe shape B in Set 3:

Obtuse scalene

Octagon with all equal sides and angles; shares the attributes of shapes in Set 1.

No

Examples on “non-polygons”

Regular polygons:

= have all equal sides and equal angles

Irregular Polygons:

= all sides are not equal and all angles are not equal

Convex Polygons:

= all angles are less than 180 degrees

Concave Polygons:

= has at least one angle larger than 180 degrees

Work in text pages 216 - 218