$\"\"$

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The vertices of triangle are $\"\"$ and $\"\"$ .

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Graph the triangle with the vertices.

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Label $\"\"$ and $\"\"$ .

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$\"\"$

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The vectors can go in either direction, so find the vectors in component form for each initial point.

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The vector $\"\"$ is line joining the vertices $\"\"$ .

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$\"\"$

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$\"\"$ .

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The vector $\"\"$ is line joining the vertices $\"\"$ .

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$\"\"$

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$\"\"$ .

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The vector $\"\"$ is line joining the vertices $\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$

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Find the angle between $\"\"$ and $\"\"$ .

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The vertex $\"\"$ must be the initial point of both vectors. Thus, use $\"\"$ and $\"\"$ .

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The angle between two vectors is $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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Find the angle between $\"\"$ and $\"\"$ .

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The vertex $\"\"$ must be the initial point of both vectors. Thus, use $\"\"$ and $\"\"$ .

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The angle between $\"\"$ and $\"\"$ is $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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The sum of angles in a triangle is $\"\"$ .

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Remaining angle is $\"\"$ .

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The three angles are about $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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The three angles are about $\"\"$ , $\"\"$ and $\"\"$ .