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
7. Non-Right Triangles
Law of Sines
Problem 7.3
Textbook Question
Textbook QuestionUse the law of sines to find the indicated part of each triangle ABC.
Find B if C = 51.3°, c = 68.3 m, b = 58.2 m
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Law of Sines
The Law of Sines states that in any triangle, the ratio of the length of a side to the sine of its opposite angle is constant. This can be expressed as a/b = sin(A)/sin(B) = c/sin(C). It is particularly useful for solving triangles when two angles and one side (AAS or ASA) or two sides and a non-included angle (SSA) are known.
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Angle and Side Relationships
In triangles, the relationship between angles and sides is crucial. The larger the angle, the longer the opposite side. This principle helps in determining unknown angles or sides when some values are given, as seen in the Law of Sines, which relies on these relationships to find missing parts of the triangle.
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Solving for Angles
To find an unknown angle in a triangle using the Law of Sines, one can rearrange the formula to isolate the sine of the angle. This often involves taking the inverse sine (arcsin) of the calculated ratio. It's important to consider the possible values for angles, especially in ambiguous cases where two different triangles could satisfy the given conditions.
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