The measure of arc QS is also 128 degrees.
To find the measure of arc QS, we can use the fact that the sum of the angles in a circle formed by intersecting chords is equal to the sum of their intercepted arcs.
Given:
PQS = 128 degrees
Firstly, let's establish the relationship between the angles and arcs:
Angle PQS corresponds to arc PRS (same intercepted arc).
Angle RQS corresponds to arc QS.
The sum of angles PQS and RQS equals the sum of their intercepted arcs:
Angle PQS + Angle RQS = Arc PRS + Arc QS
We know Angle PQS = 128 degrees and Arc PRS = 128 degrees.
128 degrees (Angle PQS) + Angle RQS = 128 degrees (Arc PRS) + Arc QS
Now, solve for Angle RQS (or Arc QS):
Angle RQS = 128 degrees + Arc QS - 128 degrees
Angle RQS = Arc QS
Therefore, Angle RQS = Arc QS.
So, the measure of arc QS is also 128 degrees.