Sine Rule Lesson

Sine Rule

​Purpose

The Sine Rule (or Law of Sines) is used to solve triangle angles or sides when there is no right angle.

Specifically, the Sine Rule is applied when given information relates to two pairs of angles with their opposite sides.

The Sine Rule is based on a conventional arrangement of labels on the diagram of a triangle.
Note: an angle and opposite side are a matching upper and lower case letter. This pairing is important.

​

​Convention

​Statement of the Sine Rule

​The next three slides will take you to Khan Academy video example and a short quiz with access to support. When done, come back to this Quizizz task tab to continue.

Law of sines: solving for a side | Trigonometry (video) | Khan Academy

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Law of sines: solving for an angle | Trigonometry (video) | Khan Academy

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Solve triangles using the law of sines (practice) | Khan Academy

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Multiple Choice

Find the value of a.

• 13.4

• 12.9

• 13.0

• 12.8

Multiple Choice

Find the value of b.

• 19.3

• 20.0

• 18.5

• 19.0

Multiple Choice

Find the value of c.

• 19.4

• 31

• 15.2

• 24.2

Multiple Choice

Find the value of c.

• 24.7

• 28.2

• 23.4

• 25.3

Multiple Choice

Find the size of angle X.

• 0.6

• 36.2

• 36.9

• 36.4