Given b=10, angle B=48 degrees, angle C=58 degrees, find c
Do I use the law of sine or cosine?
43.8 :))
To determine whether to use the Law of Sines or the Law of Cosines, we need to consider the given information and the relationship we are trying to find. In this case, we are given one side (b) and two angles (B and C), and we need to find another side (c).
Since we know one side and two angles, we can use the Law of Sines. The Law of Sines relates the ratios of the lengths of the sides to the sines of their opposite angles. The formula for the Law of Sines is as follows:
sin(A)/a = sin(B)/b = sin(C)/c
Now, applying the Law of Sines to our given information:
sin(B)/b = sin(C)/c
We know that b = 10, angle B = 48 degrees, and angle C = 58 degrees. Plugging in these values into the equation, we get:
sin(48)/10 = sin(58)/c
Now, we can solve for c by rearranging the equation:
c = (10 * sin(58))/sin(48)
Using a calculator, we can evaluate sin(58) and sin(48), and then divide the product of 10 and sin(58) by sin(48) to find the value of c.
Huh. You really need to study them. Try law of sines:
c/sinC = b/sinB
law of cosines uses two sides and their included angle to find the 3rd side.