Two planes intersect

Options

A. at a point
B. in a line
C. in a plane
D. none of these

Answer

To solve the question about the intersection of two planes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Planes**: First, we need to understand what a plane is. A plane is a flat, two-dimensional surface that extends infinitely in all directions.

2. **Visualizing Two Planes**: Imagine two flat surfaces (planes) in space. For example, one plane can be horizontal (like a table), and the other can be vertical (like a wall).

3. **Identifying Intersection**: When two planes intersect, they do not meet at just one point or overlap completely. Instead, they intersect along a straight line.

4. **Conclusion**: Therefore, the intersection of two planes is a line. This means that the correct answer to the question is that two planes intersect at a line.

### Final Answer:
Two planes intersect at a line.

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