1. CHAPTER ELEVEN MATH 1A POWERPOINT PRESENTATION
GEOMETRY

2. LEARNING TARGETS AFTER YOU COMPLETE THIS CHAPTER, YOU WILL BE ABLE TO:
MEASURE AND CLASSIFY ANGLES
NAME AND CLASSIFY TRIANGLES
FIND THE MEASURE OF ANGLES IN TRIANGLES
IDENTIFY QUADRILATERALS
DETERMIN DEGREES IN POLYGONS

3. VOCABULARY INTERSECTION: THE POINT WHERE TWO LINES CROSS IN A FIGURE
RAY: PART OF A LINE THAT HAS ONE ENDPOINT AND EXTENDS INDEFINIETLY IN ONE DIRECTION
VERTEX: A COMMON POINT TO BOTH SIDES OF AN ANGLE
PROTRACTOR: A TOOL USED TO DRAW AND MEASURE ANGLES

4. INTERSECTING LINES

5. VERTEX/ANGLE/RAY

6. PROTRACTOR

7. Identifying & Classifying Angles
Adjacent: two angles with the same vertex that share a side
Vertical: angles formed by intersecting lines
Acute: an angle < 90⁰
Obtuse: an angle > 90⁰
Complementary Angles = 90⁰
Supplementary Angles = 180⁰

8. ADJACENT ANGLES

9. VERTICAL ANGLES

10. Acute/Obtuse

11. Complementary/Supplementary

12. Internal/External Angles
Internal Angles: formed by extending one side of a polygon at any vertex
Internal Angles: any angle within a polygon
Triangle – 180⁰ of internal angles
Quadrilateral (4 sided figures) – 360⁰ of internal angles
Pentagon – 540⁰ of internal angles
Hexagon – 720⁰ of internal angles
Octagon – 1080⁰ of internal angles

13. External Angles External Angles The external angle is angle w

14. Naming Triangles Tick – a short line used to mark sides in geometry
Acute Triangle – no angles >90⁰
Obtuse Triangle – one angle >90⁰
Equiangular Triangle – all angles equal
Right Triangle - one angle exactly 90⁰
When you name triangles this way, you are naming them by their angles.

15. Tick Marks

16. TYPES OF TRIANGLES

17. Other Triangles

18. Congruence Congruent Shapes – are alike in every detail.
Congruent Triangles:

19. Three Theorems to Prove Congruence
Angle-Side-Angle: (ASA) – two like angles, one like side.
Side-Side-Side: (SSS) – all sides are alike
Side-Angle-Side: (SAS) – two like sides, one like angle.
These theorems are proved by examining the ticks in the two triangles.

20. Examples of Congruence
SAS

21. Angle-Side-Angle Congruence
ASA

22. Side-Side-Side Congruence
SSS

23. Similar Shapes
Similar: figures that have the same shape but not the same size.
Corresponding Angles: interior or exterior angles in figures with the same proportions, and shape, but not the same size:

24. Quadrilaterals Quadrialterals: shapes with 4 sides:
Square and Rectangle
Parallelogram and Rhombus
Kite
Trapezoid
All Internal Angles = 360⁰

25. What Quadrilaterals Look Like

26. Diagonals
Diagonals – are line segments connecting two vertices (points) that are not next to each other.

27. Geometry – Awesome!!!!