 In this video we're going to talk about something called a median of a trapezoid. And so first I'm going to write down the definition of what a median is in a trapezoid. It is the segment that connects the midpoints of the legs. So remember that the legs are the non-parallel sides. So I'm going to draw what looks like a midpoint. And so that line or segment that I've just drawn is the median. And that there are some properties about the median. First of all it is always parallel to the bases. So on this picture I'm going to just draw arrows to show that those are all parallel. Also because it is connecting the midpoints of the legs we know that these pieces have to be congruent and these two have to be congruent. Now this is really important to understand and that is that not all four of these are congruent necessarily. But the two on this side have to be congruent because this is the midpoint of that leg. And the two on this side have to be congruent because it's the midpoint of this leg. So we've got parallel to the bases, we've got these pieces have to be congruent. And then the last thing is how to find the actual length of the median. And so the length of the median is always half of the sum of the bases. So the length of the median is one half times base one plus base two. So if I say that this is base one and this is base two, if I add those two lengths together and divide by two or multiply by half which would be the same thing you will get the length of the median.