Give exact answers no decimal answers Use either the sin law

Give exact answers, no decimal answers. Use either the sin law (2 sides, 2 angles) or the cosine law (3 Sides. 1 angle). Find the two values of A Recall if theta is a solution to sin theta = a, so is 180 degree - theta when the side opposite is

Solution

Here in question 3), we use cosine formula,

cos B=(a^2+c^2-b^2)/2ac

cos 55= (3^2+5^2-b^2)/2(3)(5)=(9+25-b^2)/30

or

0.5736(30)= 36-b^2

or

17.2=36-b^2or b^2= 36- 17.2 = 18.79

or b= root(18.79) =4.3

so measure of b is 4.3

Answer