Activating Prior Knowledge- On your warm up page, draw and label a set of parallel lines. On your warm up page, draw and label a set of perpendicular lines. CFU

identify parallel and perpendicular lines. Learning Objective Today, we will identify parallel and perpendicular lines. CFU

Concept Development – Notes #1 & 2 (No Notes) These two lines are parallel. 1. Parallel lines are lines in the same plane that have no points in common. 2. In other words, they do not intersect. CFU

Concept Development – Notes #3 CFU

Concept Development - CFU Draw a line through point (1,1) with a slope of 2. Draw a line that is parallel to this line. CFU

What do I know about the slopes of parallel lines? Concept Development - How would I identify which lines are parallel? y = − 𝟏 𝟑 x + 2 y = 3x + 1 y = -3x+1 y = 3x What do I know about the slopes of parallel lines? CFU

What do I need to do first to identify the slope? Concept Development - How would I identify which lines are parallel? 2x + y = 2 y = -2x+1 6x + 3y = 9 y + 4x = 1 What do I need to do first to identify the slope? CFU

Skill Development/Guided Practice – Notes #4 Identify which lines are parallel. y = 2x + 2; y = 2x + 1; y = –4; x = 1 y = 2x + 2 The lines described by y = 2x + 2 and y = 2x + 1 represent parallel lines. They each have slope 2. y = 2x + 1 Equations x = 1 and y = –4 are not parallel. y = –4 x = 1 CFU

Skill Development/Guided Practice – Notes #5 Identify which lines are parallel. Write all equations in slope-intercept form to determine the slope. y = 2x – 3 slope-intercept form   slope-intercept form CFU

Skill Development/Guided Practice – Cont. Notes #5 Identify which lines are parallel. Write all equations in slope-intercept form to determine the slope. 2x + 3y = 8 y + 1 = 3(x – 3) –2x – 2x y + 1 = 3x – 9 3y = –2x + 8 – 1 – 1 y = 3x – 10 CFU

Skill Development/Guided Practice – Cont. Notes #5 The lines described by y = 2x – 3 and y + 1 = 3(x – 3) are not parallel with any of the lines. The lines described by and represent parallel lines. They each have the slope . y = 2x – 3 y + 1 = 3(x – 3) CFU

y = 2x + 9 Concept Development - CFU Find the slope of a line parallel to each given line. y = 2x + 9 CFU

y = -3x Concept Development - CFU Find the slope of a line parallel to each given line. y = -3x CFU

2x + y = 4 Concept Development - CFU Find the slope of a line parallel to each given line. 2x + y = 4 CFU

3x + y = 1 Concept Development - CFU Find the slope of a line parallel to each given line. 3x + y = 1 CFU

Concept Development – Notes #6 Perpendicular lines are lines that intersect to form right angles (90°). CFU

Concept Development - Whiteboard Graph the line y = 2x + 3. Write an equation that is perpendicular to y = 2x + 3. Graph that line. CFU

Concept Development - Whiteboard How would I identify which lines are perpendicular? y = − 𝟏 𝟑 x + 2 y = 3x + 1 y = -3x+1 y = 3x What do I know about the slopes of perpendicular lines? CFU

Skill Development/Guided Practice – Notes #7 Identify which lines are perpendicular: y = 3; x = –2; y = 3x; . The graph given by y = 3 is a horizontal line, and the graph given by x = –2 is a vertical line. These lines are perpendicular. x = –2 y = 3 The slope of the line given by y = 3x is 3. The slope of the line described by is . y =3x CFU

Skill Development/Guided Practice – Cont. Notes #7 Identify which lines are perpendicular: y = 3; x = –2; y = 3x; . x = –2 y = 3 These lines are perpendicular because the product of their slopes is –1. y =3x CFU

Closure – Paper CFU 1. What did we learn today? 2. Why is this important to you? 3. Two parallel lines will have slopes that are ________? 4. Write two linear equations in slope-intercept form that are parallel. CFU