Well, it's been a while since I've answered a question on this website, and what better way to celebrate with a geometry question :)
So, we don't have a right triangle, so we're gonna have to settle with Law of Cosines.
Also, note that we have
(cosPMQ)=(−cosPMR)
Now, let's apply Law of Cosines and add subsitute using equation above.
PQ2=QM2+PM2−2(QM∗PM)∗(−cosPMR)PR2=RM2+PM2−2(RM∗PM)∗(cosPMR)
Simplify
52=5.52+PM2+2(5.5∗PM)cos(PMR)82=5.52+PM2−2(5,5∗PM)cos(PMR)
Now, we're stuck...but we can add these two equations to keep progressing.
52+82=2∗5.52+2PM289=60.5+2PM228.5/2=PM214.25=PM2√14.25=PM≈3.77
And we're done!
Also, side note, this is gonna be my 1000 answer on this website which is a weird flex but whatever.
I might be gone for another while, but hopefully be back in the summer.
~NTS