1. 1. Name 4 ways to show two lines are parallel
UNIT Perpendicular Lines
1. Name 4 ways to show two lines are parallel
2. If m||n, find the measure of as many angles as possible C m n o
140°
30° 1

2. 3. Given: a||b,25 Prove: m||n UNIT 3 Perpendicular Lines 3.4 a b 21 2 a b m n 5 3 4

3. UNIT 3 Perpendicular Lines 3.4
How to you calculate the distance from a point to a line?
Name the shortest segment from point A to BC.
Write and solve an inequality for x.

4. UNIT 3 Perpendicular Lines 3.4
If two lines intersect forming a linear pair of congruent angles, then the lines are perpendicular.
If a transversal is perpendicular to one pair of parallel lines, then it is perpendicular to both lines.
If two lines are perpendicular to the same line,
Then the two lines are parallel.

5. UNIT 3 Perpendicular Lines 3.4
What is “slope”?

6. UNIT Slopes of Lines
Use the slope formula to determine the slope of each line.

7. UNIT Slopes of Lines
The slopes of parallel lines are equal.
The slopes of perpendicular lines are “opposite reciprocals”.

8. UNIT Slopes of Lines
Mr. Mack is driving home from Minnesota. At 7:00am he was 800 miles from home. At 10:00am he was 650 miles from home.
Graph a line representing the distance from his home and find the slope
What does the slope represent?
What time will Mr. Mack arrive home?
What time will Mr. Mack be 108 miles from home?

9. UNIT Slopes of Lines
Determine whether the lines are parallel, perpendicular, or neither.
UV and XY for U(0, 2), V(–1, –1), X(3, 1), and Y(–3, 3)
CD and EF for C(–1, –3), E(–1, 1), D(1, 1), and F(0, 3)
GH and IJ for G(–3, –2), H(1, 2), I(–2, 4), and J(2, –4)

10. UNIT Slopes of Lines
Determine whether the lines are parallel, perpendicular, or neither.
UV and XY for U(0, 2), V(–1, –1), X(3, 1), and Y(–3, 3)
GH and IJ for G(–3, –2), H(1, 2), I(–2, 4), and J(2, –4)
CD and EF for C(–1, –3), D(1, 1), E(–1, 1), and F(0, 3)

11. Assignment
3.4(175): 13-21,24
answers: 14:25,40 16:yes 18:no 20:yes 24:6,6
3.5(185):10-18
answers: 10:undef 12:-1 14:150, speed (in miles/hour) 16:neither 18:≈ , average rate of change in elevation of the river