Circle : Diameter ::?:?

Options

A. Rectangle : Diagonal
B. Diameter: Radius
C. Square : Rectangle
D. Bisector : Angle

Explanation

To solve the analogy "Circle : Diameter :: ? : ?", we need to identify the relationship between the first pair of words (Circle and Diameter) and find a similar relationship in the second pair.

### Step-by-Step Solution:

1. **Identify the Relationship**:
- A circle is a geometric shape, and the diameter is a line segment that passes through the center of the circle and touches two points on its boundary. The diameter divides the circle into two equal halves.

2. **Find a Similar Pair**:
- We need to find a pair of words where the second word divides the first word into two equal parts, just like the diameter divides the circle.

3. **Evaluate the Options**:
- **Option 1: Rectangle, Diagonal**:
- A diagonal of a rectangle divides it into two equal triangles. This fits the relationship.
- **Option 2: Diameter, Radius**:
- The radius does not divide the diameter into two equal parts; it is a different relationship.
- **Option 3: Square, Rectangle**:
- A square is a specific type of rectangle, but it does not divide it into equal parts.
- **Option 4: Bisector, Angle**:
- A bisector divides an angle into two equal parts, but the relationship is reversed in the analogy.

4. **Choose the Correct Option**:
- Since the diagonal of a rectangle divides it into two equal parts, the correct answer is **Option 1: Rectangle, Diagonal**.

### Final Answer:
**Rectangle : Diagonal**