How do you determine whether triangle ABCABC has no, one, or two solutions given A=75^circ, a=14, b=11A=75,a=14,b=11?

1 Answer
Oct 21, 2017

A=75^o, B= 40.63^o, C = 64.37^oA=75o,B=40.63o,C=64.37o

a =14, b=11, c= 13.07a=14,b=11,c=13.07

Explanation:

I'm not sure what you mean by no, one or two solutions. We can solve the triangle completely with the given information. So in that respect it will have one solution.

Using Sine Rule:

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

sin(75)/14=sin(B)/11=>sin(B)= (11sin(75))/14sin(75)14=sin(B)11sin(B)=11sin(75)14

B= arcsin((11sin(75))/14)=40.63^oB=arcsin(11sin(75)14)=40.63o (2 .d.p.)

C = 180-(75+40.63)=64.37^oC=180(75+40.63)=64.37o

sin(75)/14=sin(64.37)/c=>c=(14sin(64.37))/sin(75)=13.07sin(75)14=sin(64.37)cc=14sin(64.37)sin(75)=13.07 (2 .d.p.)

So:

A=75^o, B= 40.63^o, C = 64.37^oA=75o,B=40.63o,C=64.37o

a =14, b=11, c= 13.07a=14,b=11,c=13.07