Table of contents
- 0. Review of College Algebra4h 43m
- 1. Measuring Angles39m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
1. Measuring Angles
Complementary and Supplementary Angles
Problem 9
Textbook Question
CONCEPT PREVIEW Name the corresponding angles and the corresponding sides of each pair of similar triangles. (EA is parallel to CD.)
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1
Identify the two triangles in the problem. Let's call them Triangle 1 and Triangle 2.
Since EA is parallel to CD, use the property of parallel lines to identify corresponding angles. Corresponding angles are equal when a transversal crosses parallel lines.
Label the angles in Triangle 1 and Triangle 2. For example, if angle A in Triangle 1 corresponds to angle D in Triangle 2, then angle A = angle D.
Identify the corresponding sides of the triangles. Corresponding sides are proportional in similar triangles.
List the pairs of corresponding angles and sides. For example, if side AB in Triangle 1 corresponds to side DE in Triangle 2, then AB/DE = BC/EF = CA/FD.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Similar Triangles
Similar triangles are triangles that have the same shape but may differ in size. This means that their corresponding angles are equal, and their corresponding sides are in proportion. Understanding the properties of similar triangles is essential for identifying corresponding angles and sides, which is crucial in solving problems related to geometry and trigonometry.
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Corresponding Angles
Corresponding angles are pairs of angles that are in the same relative position at each intersection where a straight line crosses two others. In the context of parallel lines and transversals, corresponding angles are equal. This concept is vital when analyzing similar triangles, as it helps establish the equality of angles, which is a key characteristic of similarity.
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Parallel Lines and Transversals
When a transversal intersects two parallel lines, it creates several pairs of angles, including corresponding angles, alternate interior angles, and consecutive interior angles. The properties of these angles are fundamental in proving that triangles are similar. In the given question, recognizing that EA is parallel to CD allows us to apply these properties to identify corresponding angles and sides in the similar triangles.
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Example 1
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