+150 \(MQ=QR=RP\)
\(\angle QMR=\angle QRM=x\)
\(\angle MQR=180-2x\)
\(\angle RQP=\angle RPQ=180-(180-2x)=2x\)
\(\angle QRP=180-2x- 2x=180-4x\)
\(\angle MRN=180-(180-4x)-x=3x\)
because \(\angle NMR=\angle NRM \) we know that \(MN=NR\)
\(MN=NQ=NR\)
\(\angle NMQ=\angle NQM=\angle NRQ=\angle NQR=4x\)
\(\angle MQN+\angle NQR+\angle RQP=180\)
\(4x+4x+2x=180\)
\(x=18\) (C)
