3.1 & 3.2 Identify Pairs of Lines and Angles Use Parallel Lines and Transversals
NameDefinitionPicture Parallel lines Intersecting lines Lines that never intersect. Lines that cross at one point
Perpendicular lines Oblique lines Lines that cross forming right angles Intersecting lines that aren’t perpendicular
Coplanar Skew Lines on the same plane Lines not on the same plane and don’t intersect
1. Use each of the vocabulary words to describe the picture. TermExample Parallel lines Intersecting lines Perpendicular lines Oblique lines Coplanar Skew Line m and n
NameDescriptionExample Transversal Line that intersects two or more coplanar lines at different points Transversal
Corresponding Angles same relative position Ex. top left
Alternate Interior Angles Opposite sides, inside lines
Alternate Exterior Angles Opposite sides, outside lines
Consecutive Interior Angles Same side, inside lines
If the two lines are parallel then something magical happens!!!!!! 50° 130° 50° 130°
Corresponding Angles 1 5 2 6 3 8 4 7
Alternate Interior Angles 3 6 4 5
Alternate Exterior Angles 1 7 2 8
Consecutive Interior Angles m 3 + m 5 = 180° m 4 + m 6 = 180°
2. Find the missing variables. Explain your reasoning. 80° x = _________________________ Angle Relationship: ____________ y = _________________________ Angle Relationship: ____________ 80° Vertical angles 80° Corresponding Angles
2. Find the missing variables. Explain your reasoning. x = _________________________ Angle Relationship: ____________ y = _________________________ Angle Relationship: ____________ 60° Supplementary angles 120° Alt. Int. Angles 120° 60°
2. Find the missing variables. Explain your reasoning. x = _________________________ Angle Relationship: ____________ y = _________________________ Angle Relationship: ____________ 50° Consecutive Interior Angles 130° Vertical angles 130° 50°
2. Find the missing variables. Explain your reasoning. Angle Relationship: ____________ x = _________________________ Alternate Interior Angles 2x = 80 40°
2. Find the missing variables. Explain your reasoning. Angle Relationship: ____________ x = _________________________ Corresponding Angles x – 10 = °
2. Find the missing variables. Explain your reasoning. Angle Relationship: ____________ x = _________________________ Consecutive Interior Angles 2x = ° 2x = 70
3. Solve for x and y. Corresponding Angles 3x = 60 x = 20°
3. Solve for x and y. Corresponding Angles 3x = 60 x = 20° Consecutive Interior Angles 5y – = 180 5y = 180 5y = 50 y = 10°
4. Solve for x and y. Consecutive Interior Angles 10x + 90 = x = 90 x = 9°
4. Solve for x and y. Consecutive Interior Angles 10x + 90 = 180 Consecutive Interior Angles 2(2y – 11) + 7y + 4 = x = 90 x = 9° 4y – y + 4 = y – 18 = y = 198 y = 18°
If there is a line and a point not on the line, then there is exactly one line through the given point parallel to the given line. Parallel Postulate P
If there is a line and a point not on the line, then there is exactly one line through the given point perpendicular to the given line. Perpendicular Postulate P
Construct a Parallel Line through the point: P A
HW Problem 3.2 #28 2x + 90 = 180 x = 45° 2x = 90 SectionPage #Assignment Spiral ?s , 18-21, odd, 16-19, 23, 25, 28, 31,
3.2 #28 **Bring your compass and ruler tomorrow! 2x + 90 = 180 x = 45° 2x = 90 3y + 6y = 180 y = 20° 9y = 180 HW Problem SectionPage #Assignment Spiral ?s , 18-21, odd, 16-19, 23, 25, 28, 31,