## Abbie23 Group Title Find the length of a if the measure of angle A equals 62 degrees b = 15, and c = 21. 2 years ago 2 years ago

1. some1 Group Title

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2. some1 Group Title

Do you know if one of the angles are 90 degrees? I mean in the problem, not in the picture i just drew.

3. Abbie23 Group Title

Idts

4. Cortegu10 Group Title

i seen this prob before

5. some1 Group Title

ok then i'm not sure. Because you can use sin, cos, tan only when it's a right triangle. sorry :(

6. Abbie23 Group Title

It's okay!

7. dpaInc Group Title

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8. dpaInc Group Title

do you know the law of cosines?

9. AravindG Group Title

ya use law of cosines

10. Abbie23 Group Title

Yes, it's Law of Cosines problem

11. Cortegu10 Group Title

use law of sine here

12. dpaInc Group Title

a^2 = 21^2 + 15^2 - 2*21*15cosA

13. AravindG Group Title

$\huge \cos A =\frac{b^2+c^2-a^2}{2bc}$

14. Abbie23 Group Title

Ok!

15. AravindG Group Title

:)

16. AravindG Group Title

no rewards?

17. Abbie23 Group Title

Everyone gets one!

18. AravindG Group Title

bt i didnt get any medals :(