In Exercises 27 to 35, complete the formal proof of each theorem.
If two angles are supplementary to the same angle, then these angels are congruent.
Given: 

Prove: 

(HINT: See Exercise 27 for help.)
Elementary Geometry For College Students, 7e
Statistics for The Behavioral Sciences (MindTap Course List)
Probability and Statistics for Engineering and the Sciences
Trigonometry (MindTap Course List)
Calculus: Early Transcendentals
Elements Of Modern Algebra
Finite Mathematics
Finite Mathematics for the Managerial, Life, and Social Sciences
Calculus: Early Transcendental Functions
Contemporary Mathematics for Business & Consumers
Intermediate Algebra
Calculus: Early Transcendental Functions (MindTap Course List)
Essentials of Statistics for The Behavioral Sciences (MindTap Course List)
Elementary Technical Mathematics
Calculus of a Single Variable
Calculus (MindTap Course List)
Calculus: An Applied Approach (MindTap Course List)
Single Variable Calculus: Early Transcendentals
Applied Calculus for the Managerial, Life, and Social Sciences: A Brief Approach
Multivariable Calculus
Single Variable Calculus
Finite Mathematics and Applied Calculus (MindTap Course List)
Precalculus: Mathematics for Calculus (Standalone Book)
Single Variable Calculus: Early Transcendentals, Volume I
Understanding Basic Statistics
Mathematical Applications for the Management, Life, and Social Sciences
Essentials Of Statistics
Mathematical Excursions (MindTap Course List)
Study Guide for Stewart's Multivariable Calculus, 8th
Study Guide for Stewart's Single Variable Calculus: Early Transcendentals, 8th
Introduction To Statistics And Data Analysis
Mathematics For Machine Technology
Research Methods for the Behavioral Sciences (MindTap Course List)
Multivariable Calculus
College Algebra (MindTap Course List)
Statistics for Business & Economics, Revised (MindTap Course List)
Research Methods for the Behavioral Sciences (MindTap Course List)
Calculus (MindTap Course List)
STATISTICS F/BUSINESS+ECONOMICSTEXT
Functions and Change: A Modeling Approach to College Algebra (MindTap Course List)
Essentials Of Statistics For Business & Economics
Mathematics: A Practical Odyssey
Discrete Mathematics With Applications
A First Course in Differential Equations with Modeling Applications (MindTap Course List)
Modern Business Statistics with Microsoft Office Excel (with XLSTAT Education Edition Printed Access Card) (MindTap Course List)