Answer:
BC = 17.2.
Step-by-step explanation:
Since CAB = 90º, this is a right triangle.
The triangle format is given below:
C
A B
We have that AB = 8.6, and angle B measures 60º.
Length of BC:
BC is the hypotenyse.
Side AB is adjacent to angle B = 60º.
In a right triangle, angle
, it's adjacent side with length s and the hypotenuse h are related by the cosine of the angle, that is:

In this question, we have an angle of 60º, with has cosine 0.5. We also have that side AB = s = 8.6, and the hypotenuse h is side BC. So





BC = 17.2.
Well in a right angle triangle, we know that angle C would be 90 degrees, we can check this by solving for X and seeing if the expression 2x will give us a value of 90 degrees.
So 2x = 90
X = 90/2
X = 45 degrees.
90 = 2x
90 = 2(45)
90 = 90.
Thus since the equation is true, X = 45 degrees, we can also solve for the remaining angles knowing what X is.