# how do you find the angles of a triangle when...

Discussion in 'The Lounge' started by colbystephens, Oct 11, 2006.

1. ### colbystephens1 ton statusGMOTM Winner

Joined:
Feb 24, 2005
Posts:
10,924
20
Location:
Oregon
you only have the three lengths of the sides? this is not a right triangle.

Joined:
Oct 16, 2005
Posts:
1,065
0
Location:
here
Depends.

Joined:
Feb 24, 2005
Posts:
10,924
20
Location:
Oregon

Joined:
Feb 24, 2005
Posts:
10,924
20
Location:
Oregon
on?

5. ### bear761/2 ton status

Joined:
Oct 16, 2005
Posts:
1,065
0
Location:
here
If I know it from memory or have to figure it out. Triangle angles = 180* find the ratio of the sides to each other and divide 180* by those ratios. Ratios with 1-1-2 the angles = 45*45*90*. I'm not a teacher, that the best I can explain it.

6. ### josh86k101/2 ton status

Joined:
Feb 13, 2005
Posts:
423
1
Location:
Knoxville, TN
Sin(x)=opposite/ hypotenuse

Inverse of the above, when the appropriate lengths for the trig function are entered should give you the value of x.

sin^-1(opp/hyp)=x
and so on.

Right? its been a while since trig.

7. ### BigBen1/2 ton statusPremium Member

Joined:
Nov 14, 2002
Posts:
1,194
0
Location:
Grand Haven, MI
Correct.

8. ### hunterguy861/2 ton status

Joined:
Jan 10, 2005
Posts:
2,477
0
Location:
San Marcos, Texas
That would be it. I'm taking this damn class right now. I hate trig...........

9. ### mofugly131 ton bucket of rustPremium Member

Joined:
Oct 6, 2002
Posts:
2,813
2
Location:
San Francisco
Trig only works on right triangles, right?

10. ### colbystephens1 ton statusGMOTM Winner

Joined:
Feb 24, 2005
Posts:
10,924
20
Location:
Oregon
trig doesn't only work on right triangles, but the equations posted do only work on right triangles. the only trig function i know that does work on non-right triangles is:

a/sin(A)=b/sin(B)=c/sin(C).

Joined:
Nov 8, 2004
Posts:
1,248