Because LP and NP are the same measure, that means that MP is a bisector. It bisects side LN and it also bisects angle LMN. Where MP meets LN creates right angles. What we have then thus far is that angle LMP is congruent to angle NMP and that angle LPM is congruent to angle NPM and of course MP is congruent to itself by the reflexive property. Therefore, triangle LPM is congruent to triangle NMP and side LM is congruent to side NM by CPCTC. Side LM measures 11.
