Final answer:
Arc CDE can describe a minor arc, a major arc, or a semicircle, depending on the angle it spans, but it does not describe a chord. A minor arc is less than 180 degrees, a major arc is greater than 180 degrees but less than 360 degrees, and a semicircle is exactly 180 degrees.
Step-by-step explanation:
The question “What does arc CDE describe?” relates to the parts of a circle in geometry. In geometry, an arc is a portion of the circumference of a circle. To determine whether arc CDE is a minor arc, major arc, semicircle, or a chord, we need to consider the degree measure of the arc. A minor arc is less than 180°, a major arc is greater than 180° but less than 360°, a semicircle is exactly 180°, and a chord is a straight line segment whose endpoints both lie on the circle.
Since the question does not provide the specific degree measure of arc CDE, we can only define these terms and not determine which category arc CDE falls into without further information. However, given the provided context, where it mentions that an arc's length is proportional to its radius and is the distance along the circular path, we can infer that the question likely refers to an arc as a part of the circumference and not a chord. Therefore, the arc CDE could be a minor arc, a major arc, or a semicircle depending on its size but not a chord.