Question 1069164
So we have a triangle where you know a Side, Angle, and Side, an SAS triangle.
To solve the missing side use the Law of Cosines (it works for any triangle):
c^2 = a^2+b^2-(2ab)cos(c)
c^2 = 188^2+865^2-2(188*865)(cos42)
c^2 = 783,569-241,700.42
subtract, take the square root of the result you get, and you'll have:
Your missing side, side c, is 736.12
:
Check the illustration below, the sides are opposite to the angles. I mean:
side a is opposite to angle A, side b opposite to angle B, and side c opposite to angle C. Why did I solve for side c? Because the angle given by the problem is ACB or simply the one in the middle, C. Plus, the sides given are AC and AB.
*[illustration SAS_triangle]