Answer:
A rectangle
Step-by-step explanation:
The sum of the interior angles of a polygon with n sides is 180(n – 2)°.
A quadrilateral has four sides, so n = 4.
Sum of interior angles = 180(4 - 2)° = 180(2)° = 360°
If the quadrilateral is equiangular,
Each interior angle = 360/4 = 90°
The quadrilateral is not equilateral, so it must be a rectangle.