Since line QS is extended through point S to point T, the measure of angle RST is equal to 329°.
In Mathematics and Geometry, a supplementary angle refers to two angles or arc whose sum is equal to 180 degrees.
Since line QS is extended through point S to point T, we would have to apply the angle sum property of a straight line as follows:
m∠QRS + m∠SQR = 180°
x + 8 + x + 13 = 180°
2x + 21 = 180°
2x = 180° - 21
x = 159/2
x = 79.5°
Now, we can determine the measure of angle RST as follows;
m∠RST = 4x + 11
m∠RST = 4(79.5) + 11
m∠RST = 318 + 11
m∠RST = 329°