What is another (more descriptive) name for each polygon described below?

1. A regular polygon with an exterior angle measuring $120°$.

   Hint (a):

   $n=\frac{360°}{120°}$

2. A quadrilateral with four equal angles.

   Answer (b):

   A rectangle.

3. A polygon with an interior angle sum of $1260°$.

   Hint (c):

   $(n - 2)(180) = 1260°$

4. A quadrilateral with perpendicular diagonals that bisect each other.

   Answer (d):

   A rhombus.