Find the angles of a triangle whose vertices are `A(0,-1,-2),B(3,1,4)` and `C` (5,7,1).

Explanation

To find the angles of the triangle with vertices \( A(0, -1, -2) \), \( B(3, 1, 4) \), and \( C(5, 7, 1) \), we will follow these steps:

### Step 1: Find the position vectors
The position vectors of points \( A \), \( B \), and \( C \) are given by:
- \( \vec{OA} = 0\hat{i} - 1\hat{j} - 2\hat{k} = 0\hat{i} - 1\hat{j} - 2\hat{k} \)
- \( \vec{OB} = 3\hat{i} + 1\hat{j} + 4\hat{k} \)
- \( \vec{OC} = 5\hat{i} + 7\hat{j} + 1\hat{k} \)

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