C = 110°
a = 5
b = 11
2007-10-26 07:35:45 · 5 answers · asked by Hamid K 1 in Science & Mathematics ➔ Mathematics
Use the cosine rule to find c:
c^2 = a^2 + b^2 - 2bc * cos(C)
c^2 = 25 + 121 - 100*cos(110)
c^2 = 180.20201...
c = 13.4
Use the sine rule to find A and B:
sin(B)/b = sin(C)/c
sin(B) = b*sin(C)/c
sin(B) = (11/13.423...)sin(110)
sin(B) = 0.7700...
B = 50 degrees
sin(A) = a*sin(C)/c
sin(A) = (5/13.423...)sin(110)
sin(A) = 0.3500...
A = 20 degrees
Tip: Don't work out the third angle by subracting the other two from 180. Use the sine rule, then if the angles don't add up to 180 then you know you've made a mistake.
N.B. inverse sine has a range of -90 to 90. So an angle may be 105 degrees, but you get the answer 75, as they have the same sine.
2007-10-26 10:41:50 · answer #1 · answered by Helen B 5 · 0⤊ 0⤋
Cosinus sentence: a^2 + b^2 - 2abcosC = c^2
Then c= sq.root of(183)= 13.5
Then you can use sinus sentence
Sin A/a= Sin C/c= 0.07
sinA= 0.07 x 5= 0.35 and then A= 20.5 deg
sinB=0.07 x 11=0.77 and then B=50.6 deg
What you now do not know about this triangle triangle is
is easy to find out.
2007-10-26 08:30:15 · answer #2 · answered by anordtug 6 · 0⤊ 0⤋
Not enough information.
Natalie you can only use Pythag on right angled triangles and this one has an angle of 110
2007-10-26 07:46:46 · answer #3 · answered by Anonymous · 2⤊ 1⤋
cosine rule
a^2 + b^2 - 2abcosC = c^2
2007-10-27 03:15:48 · answer #4 · answered by stuartelliott797 2 · 0⤊ 0⤋
sine rule to find opposite angles.
Is that's what you mean...cause the question isnt clear.
edit-
thanks! i actually didnt notice that! but if you bisect the triangle, you can and then you find the sides :)
2007-10-26 07:40:09 · answer #5 · answered by ♥ 4 · 0⤊ 1⤋