Remember how we needed to have a right triangle to use SohCahToa? Well, that's no longer true. As long as your triangle is not a donkey in disguise, you can use the Laws of Sines and Cosines to solve any triangle. This lesson focuses on the Law of Sines and that proverbial donkey.

Intro and Example 1

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Deriving the Law of Sines

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Example 2

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Examples 3 and 4a

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Example 4a (Continued)

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Example 4b

Mr. Labelle shows us another Ambiguous Case in which there are two different measures for the missing angle B. Duration_10_00

Example 4b (Continued)

And here is the second possibility for angle B. Duration_9_41

Example 4c

There are three possible outcomes when solving a triangle using SSA. This is the third case. Duration_9_46

Pro Tip: The Ambiguous Case

Mr. Labelle summaries the three cases that arise as a result of using the Law of Sines to solve a triangle given SSA. Duration_3_32

Example 5

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Example 6

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Geometry 7(B) apply the Angle-Angle criterion to verify similar triangles and apply the proportionality of the corresponding sides to solve problems.

Geometry 9(A) determine the lengths of sides and measures of angles in a right triangle by applying the trigonometric ratios sine, cosine, and tangent to solve problems

Geometry 9(B) apply the relationships in special right triangles 30º-60º-90º and 45º-45º-90º and the Pythagorean theorem, including Pythagorean triples, to solve problems