So, let’s review what we learned about shapes back when we were in grade school. The rectangle, like the one you see above, consists of two sets of parallel sides (AB || CD and AC || BD) and all the interior angles (A, B, C, and D) are 90°. AB = CD and AC = BD. If all four sides are of equal length, you have a square.
If a figure has two sets of parallel sides but the angles are not equal to 90°, you have a parallelogram.
And if all four sides of your parallelogram are equal, you have a rhombus.
If you have a four-sided figure where two of the sides are equal, that’s a trapezoid.
All of these figures are called quadrilaterals (from the Latin meaning "four sides") as are figures like this one:
There will be a test later on this material. Pray for a fire drill.