`A B C` is a triangle. The bisector of the exterior angle at `B` and the bisector of `/_C` intersect each other at `Ddot` Prove that `/_D=1/2/_A`

Explanation

To prove that angle \( D = \frac{1}{2} \angle A \) in triangle \( ABC \) where \( D \) is the intersection of the bisector of the exterior angle at \( B \) and the bisector of angle \( C \), we can follow these steps:

### Step 1: Understand the angles involved
Let:
- \( \angle A = \angle A \)
- \( \angle B = \angle B \)
- \( \angle C = \angle C \)

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