Final answer:
The length of CD is 0 because triangle BCD is a degenerate triangle.
Step-by-step explanation:
To find CD, we can use the fact that angle C is congruent to angle B. This means that triangle BCD is an isosceles triangle. In an isosceles triangle, the base angles (angles opposite the equal sides) are congruent. Therefore, angle C is congruent to angle B and angle B is congruent to angle C. Since angle C is congruent to angle B, we can use the fact that the sum of the angles in a triangle is 180 degrees.
Let x be the measure of angle B (or angle C). Then, we have:
x + x + 180 = 180 degrees
2x = 0
x = 0
Since x = 0, angle B and angle C are both 0 degrees. Therefore, triangle BCD is a degenerate triangle, meaning that it is a straight line. In this case, CD would have a length of 0.