If the largest angle of a triangle is 120 degrees and it is included between sides of 1.5 and 0.5, what is the largest side of the triangle to the nearest tenth?
c²=a²+b²-2·a·b·cos(C)
c²=(1.5)² + (0.5) -2 ·(l·5) ·(0.5) ·cos(120°)
c²= 3.25
c= √3.25
c=1.802775638
To nearest tenth, c=1.8