The similar angle markers indicate that they are congruent angles, which leads to the sides being congruent. This figure is a rhombus.
So the side of 5 units is the same length as the side of 2x+19 units
Solve for x
2x+19 = 5
2x = 5-19
2x = -14
x = -14/2
x = -7
Answer: x = -7
