Draw a quadrilateral with each characteristic that is not a parallelogram. 11. two pairs of congruent angles 12. two pairs of congruent sides 13. one pair of congruent opposite angles 14. one pair of opposite sides parallel and the other pair congruent 15. The legs of the adjustable keyboard stand are connected at their midpoints. Explain why the keyboard remains level to the floor as the stand is raised and lowered.

Imagine a quadrilateral that has two pairs of congruent angles—think of a bow tie shape! This is called a kite, where the two adjacent angles are equal, and the two opposing angles differ, breaking the mold of a parallelogram’s parallel sides. Now, picture the legs of your adjustable keyboard stand. Since the legs are connected at their midpoints, they create two triangles on either side. As you raise or lower the stand, the midpoints maintain the same relative distance from the floor, keeping the keyboard perfectly level every time. When we look at the real world, take a kite on a windy day! The kite's structure allows it to fly with its unique shape, as it has congruent angles and sides, making it stable in the air—different from a parallelogram yet still captivating. Similarly, when you adjust your keyboard stand, each movement keeps those midpoints aligned, showcasing how geometry assists in practical scenarios, ensuring your workspace is comfortable and efficient.