#### 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
Brooks Cole

ISBN 10:
1439047901

ISBN 13:
978-1-43904-790-3

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

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