2. Glossary of terms Interior angle: Exterior angle: Regular polygon: Irregular polygon: Symmetry

3. Glossary of terms Interior angle: An angle on the inside of a shape Exterior angle: An angle on the outside of a shape Regular polygon: A polygon that has all its faces the same shape and size Irregular polygon: Its faces are different in shape and/or size Symmetry: A shape that is in proportion and balance

4. Interior and exterior angles Interior anglesExterior angle

5. Shapes and Angles Q. What degree of angle does a straight line equal? A. The angles on any straight line add up to 180° 90° 90° + 90° = 180° 45°135° 135° + 45° = 180° Interior angleExterior angle Interior angleExterior angle

6. Angles on parallel lines A line that intersects (crosses) parallel lines creates angles. This line is called a transversal The angles created are either: –Corresponding to each other –Alternate to each other or –Co-interior to each other (co-interior angles add up to 180°)

7. Parallel lines and angles Corresponding angles = are the same Alternate angles = are the same Co-interior angles = add up to 180°

8. Remember The interior and exterior angle always add up to 180° extint ext int ext

9. Angles inside a triangle The angles inside a triangle also add up to 180° 67° 33° x°x° X° + 67° + 33° = 180° X° = 80°

10. Angles inside a square A square has four 90° angles that add up to 360°

11. Polygons Polygons are closed figures that have several line segments and angles (Poly = many; gonia = angle). Triangles are polygons with three sides. Quadrilaterals are polygons that have four sides (quattuor = four, lateralis = side).

12. Some of the quadrilaterals are so special that they have they own names.

13. Common Polygons Parallelograms have their opposite sides parallel. In rectangles all the angles are right angles.

14. More common polygons A square has four right angles and all sides are equal Pentagons have 5 sides and 5 angles (pente = five, gonia = angle). regular irregular

15. Even more common polygons Hexagons have 6 sides and 6 angles (hex = six). regular irregular regular or Irregular?