1. Parallel and Perpendicular 1/4 lines
Parallel lines: 2 different lines that have the same slope and will never touch
*If 2 NONVERTICAL lines are parallel they have the same slope
*If 2 parallel lines are vertical, they are UNDEFINED.

2. Perpendicular lines
Perpendicular lines have a slope that is both INVERSE and NEGATIVE to each other
If the slope of line 1 is 4
Then…
Perpendicular line slope is -1/4
** They make RIGHT angles

3. The Distance and Midpoint Formulas

4. Distance Formula Used to find the distance between two points
**** YOU MIGHT NOT GET A PERFECT SQUARE. IN THIS CASE, LEAVE IT IN SQUARE ROOT FORM

5. Using the Distance formula
To find the distance between 2 spots you need to know WHERE THE 2 SPOTS ARE!!
There will be 2 “X” values to work with
There will also be 2 “Y” values to work with

6. When given 2 sets of coordinates….see sheet
Plug these in
to the formula
A ( 9, 14) B ( 8, 3)
X1 = 9 X2 = 8
Y1 = Y2 = 3

7. Example
Find the distance between A(4,8) and B(1,12)
A (4, 8)
B (1, 12)

8. Solve for distance: Example 1

9. YOU TRY!! Find the distance between: A. (2, 7) and (11, 9)
B. (-5, 8) and (2, - 4)

10. triangle has equal sides
Can be used to find if a
triangle has equal sides
IF YOU USE THE DISTANCE FORMULA TO CALCULATE THE SIDDES OF A TRIANGLE, YOU CAN DETERMINE IF THE TRIANGLE HAS EQUAL SIDES. A
Measure distance AB BC AC B C

11. Midpoint Formula
Used to find the center of a line segment
*** THE MIDPOINT FORMULA FINDS THE EXACT MIDDLE OF A LINE SEGMENT***

12. Example
Find the midpoint between A(4,8) and B(1,12)
A (4, 8)
B (1, 12)

13. YOU TRY!! Find the midpoint between: A) (2, 7) and (14, 9)
B) (-5, 8) and (2, - 4)

14. You try it…..
Homework:
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