1. anonymous

2. anonymous

Use pythagorean theorem to get your third side, then use triangular trig ratios to get the trig functions... like sin(theta)=opp/hyp, cos(theta)=adj/hyp, etc...

3. anonymous

There is a nice little short cut too... once you find sin, cos, and tan... csc, sec, and cot are the reciprocals.

4. anonymous

@EulerGroupie is it A then??? the first choice?

5. anonymous

That is not what I got. What did you get for the missing side?

6. anonymous

12/3sqrt41

7. anonymous

eek!$c ^{2}=a ^{2}+b ^{2}$where c is the hypotenuse. You have c and a... solve for b$b=\sqrt{c ^{2}-a ^{2}}$

8. anonymous

It comes out nice... not irrational. What do you get for the missing side now?

9. anonymous

9?

10. anonymous

Yes

11. anonymous

Now, all of those trig functions have angle A in them... so you are looking at the triangle from that corner. If that's the case, then 9 is your adjacent side, 12 is your opposite side, and 15 is the hypotenuse. So what is sin A=opp/hyp?

12. anonymous

4/5

13. anonymous

Yes! Now cos A=adj/hyp... which is?

14. anonymous

3/4

15. anonymous

sorry thats not it!!

16. anonymous

Not what I got. adj=9, hyp=15...

17. anonymous

3/5

18. anonymous

Yes! tan?

19. anonymous

what is the equation for tan?

20. anonymous

21. anonymous

4/3 :)

22. anonymous

Yes!

23. anonymous

thank you, I understand the rest now

24. anonymous

Awesome! You're welcome.