Question

In Quadrilateral ABCD, AB II DC and BC II AD. What MUST be true about Quadrilateral ABCD?
Please explain this to me! @Geometry

Answer 1

It must have opposite sides of the same length, you can't draw a trapezoid, for instance since all the sides are the same length and parallel. There are only up to 2 different angles within your quadrilateral, but there is no reason to believe that they are all 90 degrees or not. So you can't say that it's a square or rectangle, although it is possible, at the very least you know it's a parallelogram.