To determine if quadrilateral QRST is a parallelogram, we can use the properties of its angles. For quadrilaterals, the sum of the interior angles equals 360 degrees. We know that angle Q measures 108 degrees, angle R measures \(108 - 2x\), and we can find angles S and T using the coordinates to calculate their slopes and subsequently their angles. However, a simpler approach to analyzing the interior angles can be done here as well.
Assuming that QRST is a parallelogram, the opposite angles must be equal. Thus, angle S must equal angle R and angle T must equal angle Q. To verify if QRST can be a parallelogram, moments involving angles must equal 360 degrees. We can solve:
\[ 108 + (108 - 2x) + angle S + angle T = 360 \]
This implies that \(angle S + angle T = 144 + 2x\). Since \(angle Q\) and \(angle S\) are opposite, and so are \(angle R\) and \(angle T\), it establishes that the angles should match oppositionally for parallels, meaning each spheres sides expand 108 together canceling out both recognizing where peep angles exist.
However, without directly calculating angle S and angle T, if we presuppose them to equal the same addend and find \(108 = 108 - 2x\). This indicates:
\[ 108 - 2x = 108 \] \[ 2x = 0 \Rightarrow x = 0 \]
Therefore, if x = 0 received maintaining parallelism, with all angles satisfying adds up, proportionate to guidelines leading to local equivalency, QRST is substantiated as a parallelogram.