If `veca.vecb=0`, then what is the angle between `veca" and "vecb`?

Explanation

To solve the problem, we need to determine the angle between two vectors \( \vec{a} \) and \( \vec{b} \) given that their dot product is zero, i.e., \( \vec{a} \cdot \vec{b} = 0 \).

### Step-by-Step Solution:

1. **Understand the Dot Product**: The dot product of two vectors \( \vec{a} \) and \( \vec{b} \) is defined as:
\[ \vec{a} \cdot \vec{b} = |\vec{a}| |\vec{b}| \cos(\theta) \]
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