Answer:
See below.
Explanation:
<QPM = <RPM
<MPN + <PMN = 90
<PMN = 90 - <MPN
< Q + <R = 180 - 2QPM
So 1/2( <Q + <R) = 90 - QPM
<PMN = <RPM + <R
<PMN + <RPM + <R = 90.
180 - <PMN = <Q + < RPN
So we have :
<Q + <RPM = 180 - <PMN
<R + <RPM = 90 - <MPN
Subtracting:
<Q - <R = 90 - <PMN + < MPN
= 90 - (90 - <MPN) + <MPN
So <Q - <R = 2<MPN
MPN = 1/2 (<Q - <R).