Answer:
BCE = 90 degrees
Explanation:
We can find the measure of angle ABC because we already know the other two angles, ACB and A, and there are 180 degrees in a triangle. So, we can set up the equation 90 + 56 + B = 180. If we solve this, it comes out to B = 34 degrees. It's given that angle B and ECD are congruent, so ECD also equals 34.
Because line segment DCA is a straight line, angles ECD, BCE, and ACB will add up to 180 degrees, since they make up a straight angle. So, we can set up the equation 34 + 56 + BCE = 180, which solves out to BCE = 90 degrees, so BCE is equal to 90 degrees.