In an isosceles trapezoid the bases are parallel to each other, as represented in the image you provided.
Also remember that the legs are congruent, or the same.
So...
12 = y + 6
If 12 is the length of one leg, we will need to subtract 6 from 12 to get y. Now this is simple.
Y= 6
So to find the length of XY we will plug in our y value.
6 + 1 = 7
Thus, your length for XY is 7!
Hope this helps if you have any questions let me know!
