Topics
8. Right Triangles & Trigonometry
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United States of AmericaOH
High School

8.09 Law of cosines

Lesson
Practice

Interactive practice questions

Find the length of $a$a using the law of cosines.

Round your answer to two decimal places.

A triangle with its vertices labeled as A, B, and C. The angle at vertex A measures $33^\circ$33°. The side opposite to the $33^\circ$33° angle, side $BC$BC, is labeled $a$a units, indicating its unknown length. Side $AB$AB measures $30$30 units, as shown by the scale line beneath it. Side $AC$AC measures $13$13 units. Side $AB$AB and Side $AC$AC are adjacent to the $33^\circ$33° angle at vertex A.
Easy
3min

Find the length of $a$a using the law of cosines.

Round your answer to two decimal places.

Easy
2min

Find the length of $a$a using the law of cosines.

Round your answer to two decimal places.

Easy
2min

Find the length of $q$q using the law of cosines.

Round your answer to two decimal places.

Easy
2min
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Outcomes

G.SRT.10

Explain proofs of the Laws of Sines and Cosines and use the Laws to solve problems.

G.SRT.11

Understand and apply the Law of Sines and the Law of Cosines to find unknown measurements in right and non-right triangles, e.g., surveying problems, resultant forces.

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