The problem asks us to identify which of the given arcs represents a semicircle based on the provided diagram of a circle. A semicircle is an arc that measures 180 degrees, meaning the endpoints of the arc are diametrically opposite, i.e., they form a diameter.
2025/3/28
1. Problem Description
The problem asks us to identify which of the given arcs represents a semicircle based on the provided diagram of a circle. A semicircle is an arc that measures 180 degrees, meaning the endpoints of the arc are diametrically opposite, i.e., they form a diameter.
2. Solution Steps
Let's analyze each option:
* Arc BCE: We are given that angle . Since is a central angle, the measure of arc is also . A semicircle has a measure of . So we need to determine if arc has a measure of . We don't have enough information to determine if the arc is actually 104 degrees. However, since appears to be the top of the circle, could represent something close to a diameter. and would not be opposite.
* Arc CEA: The straight line passing through point is a tangent. Therefore, is the top most point. Also looks like it might be a diameter. If is a diameter, the arc would be equal to 180 degrees. Since looks like a reasonable diameter, let us assume passes through point . Then is a reasonable choice.
* Arc GBC: We know arc measures . We don't have enough information to determine if the remaining arc would give a sum of 180 degrees. But just by inspection, is much less than 180-76 =
1
0
4.
* Arc FCB: We know arc measures . We don't have enough information to determine if the remaining arc would give a sum of 180 degrees. But just by inspection, is much greater than
1
0
4.
Based on the diagram, it appears that is a diameter, therefore is an approximate semicircle.
3. Final Answer
CEA