A dip circle shows an apparent dip of `60^@` at a place where the true dip is `45^@`. If the dip circle is rotated through `90^@`, what apparent dip will it show?

Explanation

To solve the problem, we need to understand the relationship between true dip, apparent dip, and the orientation of the dip circle.

### Step-by-Step Solution:

1. **Understanding True Dip and Apparent Dip**:
- The true dip is the angle between the horizontal plane and the plane of the geological structure. In this case, the true dip is given as 45°.
- The apparent dip is the angle that a dip circle shows when it is not aligned with the true dip direction. Here, the apparent dip is given as 60°.

...