As shown in the figure, P is in ∠ AOB, and points m and N are the symmetrical points of point P about OA and ob respectively. If Mn = 10cm, calculate the perimeter of triangle PEF

As shown in the figure, P is in ∠ AOB, and points m and N are the symmetrical points of point P about OA and ob respectively. If Mn = 10cm, calculate the perimeter of triangle PEF

The title is incomplete, but you can guess:
E. F is the intersection of Mn, OA and ob, right?
Then △ PEF perimeter = Mn = 10cm
Because points m and N are symmetric points of point P about OA and ob respectively,
So OA and ob are the bisectors of isosceles △ mop and isosceles △ NOP,
OA ⊥ MP, ob ⊥ NP;
Similarly, in isosceles △ MEP and isosceles △ NFP,
PE=ME,FP=NF；
So △ PEF perimeter = PE + EF + FP = me + EF + FN = Mn = 10cm