Check the picture below.
let's recall that the midsegment of a triangle is the segment that's half-way to both endsides and is at the same time parallel to the 3rd side, is also half the length of the parallel side, so-called the base.
so, for example, we know L, M and N are midpoints to each segment, that means that LM is a midsegment and parallel to PR and also half the length of PR, same is true for LN and MN.
