Section 2.3 - Using Proofs in Geometry
- Angle 2 = 120 degrees since it is supplementary to angle 1. Supplementary angles are any two angles whose sum is 180 degrees.
- Angle 3 = 60 degrees since
- Angle 1 and Angle 3 are vertical angles. Vertical angles are two nonadjacent angles formed by two intersecting lines.
- Angle 4 = 120 degrees since it is supplementary to angle 1.
- Angle 5 = angle 1 by the Transversal Postulate.
- Angle 6 = angle 2, angle 7 = angle 3, and angle 8 = angle 4 by the Transversal Postulate.
- Angle 2 = angle 3 is given
- Lines R and S are parallel by the Alternate Interior Angles Converse Postulate
Section 5.1 - Methods of Proving that Triangles are Congruent
1. Yes; triangle RUN = triangle DIH by ASA
2. No; the sides and angles do not match
3. Yes; triangle SUM = triangle HRC by ASA
4. Yes; triangle QWE = triangle TYR by SSS
- Geometry Main Page
- Geometry/Chapter 1 Definitions and Reasoning (Introduction)
- Geometry/Chapter 2 Proofs
- Geometry/Chapter 3 Logical Arguments
- Geometry/Chapter 4 Congruence and Similarity
- Geometry/Chapter 5 Triangle: Congruence and Similiarity
- Geometry/Chapter 6 Triangle: Inequality Theorem
- Geometry/Chapter 7 Parallel Lines, Quadrilaterals, and Circles
- Geometry/Chapter 8 Perimeters, Areas, Volumes
- Geometry/Chapter 9 Prisms, Pyramids, Spheres
- Geometry/Chapter 10 Polygons
- Geometry/Chapter 11
- Geometry/Chapter 12 Angles: Interior and Exterior
- Geometry/Chapter 13 Angles: Complementary, Supplementary, Vertical
- Geometry/Chapter 14 Pythagorean Theorem: Proof
- Geometry/Chapter 15 Pythagorean Theorem: Distance and Triangles
- Geometry/Chapter 16 Constructions
- Geometry/Chapter 17 Coordinate Geometry
- Geometry/Chapter 18 Trigonometry
- Geometry/Chapter 19 Trigonometry: Solving Triangles
- Geometry/Chapter 20 Special Right Triangles
- Geometry/Chapter 21 Chords, Secants, Tangents, Inscribed Angles, Circumscribed Angles
- Geometry/Chapter 22 Rigid Motion
- Geometry/Appendix A Formulae
- Geometry/Appendix B Answers to problems
- Appendix C. Geometry/Postulates & Definitions
- Appendix D. Geometry/The SMSG Postulates for Euclidean Geometry