Perpendicular Lines
Plot A(2, –3) and B(2, 5). Describe the orientation of the line.
Vertical line (up and down).
Plot (–1,2) and (3,2). Describe the orientation.
Horizontal line.
Find the midpoint of (2,4) and (6,8).
(4,6)
Plot (0,0), (4,0), (4,4). Measure the angle at (4,0).
90° (right angle).
Plot (0,0) and (4,0). What is the distance direction and orientation?
Horizontal, length 4 units.
Draw a line perpendicular to a vertical line through (2, 0). Describe its orientation.
Horizontal line (left to right).
Plot the line (1, 3) and (-4, 3). Draw a parallel line through (0,5). What is the orientation?
Horizontal
Find the midpoint of (–4,2) and (4,6).
(0,4)
Plot (0,0), (5,0), (6,2). Estimate the angle at (5,0).
About 135° (obtuse).
Plot (2,2), (6,2), (6,6). What type of angle is at (6,2)?
Right angle - 90°
Plot (1,1) and (4,4). Is the line rising or falling? Draw a perpendicular line at (4,4). What is its orientation?
Original: rising right. New line: falling right.
Plot (1,1) and (4,4). Draw a parallel line through (2,3). Describe both lines. (Use rising or falling in your answer)
Both rising diagonally.
Plot (0,0) and (6,0). Find the midpoint and describe the perpendicular bisector.
Midpoint: (3,0); bisector is vertical.
Plot (0,0), (4,0), (2,3). Estimate and classify the angle.
About 60° (acute).
Plot (0,0) and (4,4). Find midpoint and describe line direction.
(2,2); rising diagonal.
Plot (–2,1) and (2,1). Draw a perpendicular line through (0,1). Describe both lines.
Original: horizontal. New: vertical.
Plot (–2,–2) and (2,2). Give the following 2 points for a parallel line through (0,1).
Plot (2,2) and (6,6). Find midpoint and describe bisector direction.
Midpoint: (4,4); bisector is falling diagonal.
Plot (1,1), (4,4), (7,2). Measure the angle at (4,4).
About 90° (right angle).
Plot (–2,0) and (2,4). Find midpoint and estimate slope direction.
(0,2); rising diagonal.
Plot (0,0) and (3,6). Describe the line’s direction. Draw a perpendicular line through (3,6). Describe its direction.
(Use the language rising or falling in your answer)
Original: rising diagonally New: falling diagonally
Plot (0,0) and (2,6). Draw a parallel line through (–2,–1). Describe the direction. (use rising or falling in your answer)
Both are rising diagonally
Plot (–2,4) and (4,10). Find midpoint and describe perpendicular bisector.
Midpoint: (1,7); bisector is falling diagonally
Create your own obtuse angle using 3 points. Measure it. What is the angle?
Answers vary (must be between 90°–180°).
Plot (0,0), (6,0), (6,3). Find angle at (6,0) and describe orientation of both lines.
90°; one horizontal, one vertical.