2. Welcome to Day 6 of School! Do Now:
Draw the figure in your notes!

3. Bell Schedule Today Period Times Length Adv. 7:42-8:28 46 minutes 1
8:31-9:22
51 minutes 2
9:25-10:16 3
10:19-11:10 4
11:13-12:04 5
12:07-12:58 6
1:01-1:52 7
1:55-2:46

4. What’s a Widget?
How did you deduce the answer?

5. What makes a good definition?
How can we use the process of deducing what a widget is to create a good definition?
A common format for a definition is:
“A ______ is a _______ that _______.”
(term) (description) (How is it different)

6. Can you find a counterexample?
What is a counterexample? Should a definition have a counterexample?
Ex: “Everyone knows ‘A square is a figure with four equal sides.’”
What is wrong with this definition?
Sketch a counterexample.
Write a better definition for a square.

7. Try These Define the following terms: Parallel Lines
Perpendicular Lines
Note the
notation for
each image

8. How did you do?
Parallel Lines: Lines in the same plane that never meet.
Why the same plane?
“Lines that never meet” can be skew lines – lines that do not intersect and are noncoplanar.
Perpendicular Lines: Lines that meet at 90° angles.

9. Types of Angles
In your group , come up with a definition for the following angles (one at a time)
Groups will then have to share their definitions.
Then compare your definitions to the “official” definition
Right Angle
Acute Angle
Obtuse Angle
Vertical Angle
Linear Pair of Angles
Complementary Angles
Supplementary Angles

10. Right Angle

11. Acute Angle

12. Obtuse Angle

13. Obtuse Angle

14. Complementary Angles

15. Supplementary Angles

16. Vertical Angles

17. Linear Angles

18. Homework
Complete the “Lesson 1.3” worksheet.

19. Exit Slip/Review:

20. Exit Slip/Review
Sketch six points A, B, C, D, E, and F, where no three of which are collinear. Name the line defined by these points. How many lines are there?
Sketch six points U, V, W, X, Y, and Z, on four lines such that each line contains three points. How many lines are concurrent at each point?