Topic 7: Reasoning in Geometry

7-1: Angles, Lines, and Transversals

Key Concept

A transversal is a line that intersects two or more lines at different points. In the diagram, line t is a transversal.

Transversal t intersects lines a and b

Corresponding angles lie on the same side of a transversal and in corresponding positions. There are four pairs of corresponding angles in this diagram: ∠1 and ∠5, ∠2 and ∠6, ∠3 and ∠7, and ∠4 and ∠8.

Alternate interior angles lie within a pair of lines and on opposite sides of a transversal. There are two pairs of alternate interior angles in this diagram: ∠3 and ∠5, and ∠4 and ∠6.

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Table of Contents

Digits, Grade 8, Volume 1, Homework Helper Unit A: Number and Operations Unit B: Proportionality Unit C: Expressions, Equations, and Relationships English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties