If one of the four angles formed by two intersecting lines is a right angle, then show that each of the four angles is a right angle.

Explanation

To prove that if one of the four angles formed by two intersecting lines is a right angle, then all four angles are right angles, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Information:**
- Let lines AB and CD intersect at point O.
- Assume angle AOD = 90° (one of the angles formed by the intersecting lines).

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