∠B = 77°, a = 7.42 and b = 12.61
Solution:
Given triangle ABC.
∠A = 35°, ∠C = 68°, c = 12
To find the measure of ∠B:
Sum of all the angles of the triangle = 180°
⇒ ∠A + ∠B + ∠C = 180°
⇒ 35° + ∠B + 68° = 180°
⇒ 103° + ∠B = 180°
⇒ ∠B = 180° – 103°
⇒ ∠B = 77°
To find the length of a and b:
The side opposite to angle A is a.
The side opposite to angle B is b.
Using law of sine,
Do cross multiplication, we get
Divide by 0.9271 on both sides, we get
⇒ a = 7.42
Again by law of sine,
Do cross multiplication, we get
Divide by 0.9271 on both sides, we get
⇒ b = 12.61
Hence ∠B = 77°, a = 7.42 and b = 12.61.
