Final answer:
In square ABCD, point E is positioned such that ABE forms an equilateral triangle. Angle CED measures 150 degrees.
Step-by-step explanation:
In square ABCD, point E is positioned such that ABE forms an equilateral triangle. To find the degree measure of angle CED, we need to use the fact that the sum of angles in a triangle is 180 degrees. Since angle ABE is an equilateral triangle, each angle in ABE is 60 degrees. Therefore, angle AED is 180 degrees - 60 degrees - 90 degrees = 30 degrees. Since angles AED and CED form a linear pair (a pair of angles that add up to 180 degrees) and angle AED is 30 degrees, angle CED must be 180 degrees - 30 degrees = 150 degrees.