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3 votes
Solve for C.

15
50°
20
c
15
Law of Cosines: c^2 = a^2+ b^2 - 2ab•cosC

c = [?]
Round your final answer to the nearest tenth.

Solve for C. 15 50° 20 c 15 Law of Cosines: c^2 = a^2+ b^2 - 2ab•cosC c = [?] Round-example-1
User JHannes
by
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1 Answer

3 votes


\textit{Law of Cosines}\\\\ c^2 = a^2+b^2-(2ab)\cos(C)\implies c = √(a^2+b^2-(2ab)\cos(C)) \\\\[-0.35em] ~\dotfill\\\\ c = √(15^2+20^2~-~2(15)(20)\cos(50^o)) \implies c = √( 625 - 600 \cos(50^o) ) \\\\\\ c \approx √( 625 - (385.6726) ) \implies c \approx √( 239.3274 ) \implies c \approx 15.5

Make sure your calculator is in Degree mode.

User Chris Schubert
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9.1k points