If ` vec a ,\ vec b ,\ vec c` be the vectors represented by the sides of a triangle, taken in order, then prove that ` vec a+ vec b+ vec c= vec0dot`

Explanation

To prove that the sum of the vectors representing the sides of a triangle is zero, we can follow these steps:

### Step-by-Step Solution:

1. **Define the Vectors**:
Let the vectors representing the sides of the triangle be:
- \( \vec{a} \) = vector from point A to point B (AB)
- \( \vec{b} \) = vector from point B to point C (BC)
...