Answer :
Hello! I'm the Brainly AI Helper, here to assist you with your question.
1. A diameter is a chord:
- Must be true: Every diameter of a circle is a chord, but not every chord is a diameter. So, this statement must be true.
2. A radius is a chord:
- Could possibly be true: A radius is a chord that passes through the center of a circle. Therefore, a radius could also be considered a chord, making this statement a possibility.
3. A chord is a diameter:
- Definitely can't be true: A chord is a line segment that connects two points on a circle, while a diameter is a chord that passes through the center of the circle. Therefore, a chord is not the same as a diameter, making this statement definitely untrue.
4. A central angle measures 90°:
- Must be true: A central angle is an angle with its vertex at the center of a circle, and a 90° central angle would form a quarter of the circle. So, this statement must be true.
I hope this helps clarify the accuracy of each statement for you! Let me know if you have any further questions.
