Search
Google ClassroomGoogle Classroom
GeoGebraGeoGebra Lesson

Outline

  1. Introduction to Deductive Geometry
    1. Theorems related to Parallel Lines
    2. Interior and Exterior Angles of Triangles

    Introduction to Deductive Geometry

    Author:Anthony OR 柯志明
    Topic:Geometry
    Introduction to Deductive Geometry

    Table of Contents

    • Theorems related to Parallel Lines

      • Angles related to parallel lines
      • Angles related to parallel lines (Converses)
      • Example 9.2
      • Example 9.3
    • Interior and Exterior Angles of Triangles

      • Angle Sum of Triangle
      • Exterior Angle of Triangle
      • Example 9.4
    Next
    Angles related to parallel lines

    New Resources

    • Pythagorean Theorem: Quick Illustrator
    • Isosceles Right Triangle
    • Midpoint Theorem (V2): Integer Solutions
    • Compound Inequality Illustrator: Conjunctions and Disjunctions
    • Function art 3D - waiting shed

    Discover Resources

    • GeoGebra Lab #1
    • Simplify Radicals
    • LEKSE UKE 45
    • สามเหลี่ยมพีทาโกรัส
    • Caterpillar

    Discover Topics

    • Arithmetic Operations
    • Quadratic Equations
    • Set Theory
    • Means
    • Piecewise Functions
    AboutPartnersHelp Center
    Terms of ServicePrivacyLicense
    Graphing CalculatorCalculator SuiteMath Resources

    Download our apps here:

    Download_on_the_App_Store_Badge_US-UK_RGB_blk_4SVG_092917

    © 2026 GeoGebra®