#### Answer

$a^{2}$ = $b^{2}$ + $c^{2}$ - 2bc cosα

#### Work Step by Step

Given the values of a,b and c
We need to find the value of α
By using the theorem 11.4.3
In triangle ABC
$a^{2}$ = $b^{2}$ + $c^{2}$ - 2bc cosα

Published by
Cengage

ISBN 10:
978-1-337-61408-5

ISBN 13:
978-1-33761-408-5

$a^{2}$ = $b^{2}$ + $c^{2}$ - 2bc cosα

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