Answer:
C. 320
Explanation:
Given:
As we can see in the photo, PR and QR are perpendicular with each other at the angle PAQ => the angle QAR = 90°
=> arc PR = 360°/2 = 180°
=> mTAU = 180° - mRAS -mSAT - mPAU = 180° - 50° + 40° + 40° = 50°
Hence, mPRU = mRAS + mSAT + mTAU + arc PQ
= 50° + 40° + 50° + 180°
= 320°