Answer: x = 32
Set (2x-4) equal to 60 and solve for x. We are able to do this because each angle of this equilateral triangle is the same (60 degrees). The single tickmarks for each segment tell us that the three sides of this triangle are the same, so that tells us we have an equilateral triangle.
2x-4 = 60
2x-4+4 = 60+4 ... add 4 to both sides
2x = 64
2x/2 = 64/2 .... divide both sides by 2
x = 32
As a check, plug in x = 32 and we should get 60 as a result:
2x-4 = 2*32-4 = 64 - 4 = 60
so the answer is confirmed