Answer:
19.5
Explanation:
Given that ΔLMN is the midsegment triangle of ΔXYZ.
Now, by the Triangle Midsegment Theorem it is clear from the diagram that, LM is half of YZ, NM is half of YX and LN is half of XZ.
Since XZ = 12 {given}, so, LN = 6
Since, LX is half of YX and equal to 6.5, so, MN = 6.5
Again , given that LM = 7
Therefore, the perimeter of ΔLMN is ( LM + MN + LN ) = ( 7 + 6.5 + 6 ) = 19.5. (Answer)