An angle of measure `0^0` is called :

Options

A. a complete angle
B. a right angle
C. straight angle
D. None of these

Answer

To solve the question "An angle of measure `0°` is called:", we will analyze the options provided and determine the correct answer step by step.

### Step 1: Understand the Definition of Angles
First, we need to understand what an angle is. An angle is formed by two rays (sides) that meet at a common endpoint (vertex). The measure of an angle is usually expressed in degrees.

### Step 2: Identify the Given Angle
The question specifies an angle of measure `0°`. This means that the two rays are overlapping completely, resulting in no visible angle.

### Step 3: Analyze the Options
Now, let’s look at the options provided:
- **Option A: Complete Angle** - A complete angle measures `360°`, which is a full rotation. Therefore, `0°` is not a complete angle.
- **Option B: Right Angle** - A right angle measures `90°`. Since `0°` is not equal to `90°`, it is not a right angle.
- **Option C: Straight Angle** - A straight angle measures `180°`. Since `0°` is not equal to `180°`, it is not a straight angle.
- **Option D: None of These** - Since none of the previous options correctly describe an angle of `0°`, this option must be considered.

### Step 4: Conclusion
Since `0°` does not fit into any of the definitions provided in options A, B, or C, the correct answer is:
**Option D: None of these.**

### Final Answer
An angle of measure `0°` is called **None of these**.

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