## anonymous one year ago n ΔABC, BC = a = 16, AC = b = 10, and m∠C = 22°. Which equation can you use to find the value of c = AB?

1. Baseballguy101

can i see the answer choices?

2. anonymous

3. anonymous

here is the picture! http://cdn.ple.platoweb.com/PCAP-ASSETS-PROD/f0e6b9bb6f804e60999f40d25bb55b7c

4. Michele_Laino

here you can apply the theorem of Carnot, namely: $\Large \begin{gathered} {c^2} = {a^2} + {b^2} - 2ab\cos \left( {22} \right) = \hfill \\ \hfill \\ = {16^2} + {10^2} - 2 \times 16 \times 10\cos \left( {22} \right) = ... \hfill \\ \end{gathered}$

5. anonymous

i dont get it?

6. Michele_Laino

ok! Now you have to compute this: $\Large \sqrt {59.30} = ...?$

7. Michele_Laino

what do you get?

8. anonymous

none of it, i've been working on this for 3 days (not this particular question) and it only gets more and more confusing

9. Michele_Laino

we have: $\large \begin{gathered} {c^2} = {a^2} + {b^2} - 2ab\cos \left( {22} \right) = \hfill \\ \hfill \\ = {16^2} + {10^2} - 2 \times 16 \times 10\cos \left( {22} \right) = \sqrt {59.30} \cong 7.7 \hfill \\ \end{gathered}$

10. Michele_Laino

am I right?

11. anonymous

yes

12. anonymous

to see it written out, makes it somewhat easier but when its a different problem and i try and do it myself, i get it wrong

13. Michele_Laino

that is a simple application of the Theorem of Carnot

14. anonymous

thank you

15. Michele_Laino

:)