How do you solve the triangle given A=116^circ, b=5, c=3A=116,b=5,c=3?

1 Answer
Feb 6, 2017

a=6.87a=6.87;
hatB=40.88°;
hatC=23.12°

Explanation:

By the cosine theorem, it is:

a^2=b^2+c^2-2bc cos hatA

Then

a^2=5^2+3^2-2*5*3*cos116°

a^2=25+9-30*(-0.44)=47.15

Then a=sqrt(47.15)=6.87

By the sines theorem, you get:

a/sin hatA=b/sin hatB

->sin hatB=(b*sin hatA)/a

=(5*sin116°)/6.87=0.65

then hatB=sin^-1 0.65=40.88°

hatC=180°-hatA-hatB=180°-116°-40.88°=23.12°