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Chapter 3. Section 3.1 & 3.2 Identify pairs of lines and angles and use parallel lines with transversals. Objective: SWBAT identify angle pairs formed by three intersecting lines, and use angles formed by parallel lines and transversals. Parallel Lines. Lines that do not Intersect
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Chapter 3 Section 3.1 & 3.2 Identify pairs of lines and angles and use parallel lines with transversals Objective: SWBAT identify angle pairs formed by three intersecting lines, and use angles formed by parallel lines and transversals.
Parallel Lines Lines that do not Intersect and are coplanar
Parallel Planes Planes that Do not Intersect
Skew Lines Lines that do Not intersect and are not Coplanar.
Ex. 1: Identify Relationships in Space • Think of each segment in the figure as part of a line. Which line(s) or plane(s) in the figure appear to fit the description?
Some More Postulates • Parallel Postulate: • If there is a line and a point not on the line, then there is exactly one line through the point parallel to the given line.
Some More Postulates • Perpendicular Postulate • If there is a line and a point not on the line, then there is exactly one line through the point perpendicular to the given line.
Transversal a line that intersects two or more coplanar lines at different points.
Vocabulary 4 types of angles formed by a transversal:
More Postulates and Theorems • Corresponding Angles Postulate • If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent
More Postulates and Theorems • Alternate Interior Angles Theorem • If two parallel lines are cut by a transversal, then the pairs of alternate interior angles and congruent.
More Postulates and Theorems • Alternate Exterior Angles Theorem • If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent.
More Postulates and Theorems • Consecutive Interior Angles Theorem • If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary.
Solve for the variable 2p 120
Use the diagram. If m 3 = 68° and m 8 = (2x + 4)°, what is the value of x? Show your steps. Example:
Homework • Textbook pg. 142 • # 4, 6, 18, 20, 22 • Textbook pg. 149 • # 4, 6, 8, 17, 19