Step 1:

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

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Let $\"\"$ , $\"\"$ and $\"\"$ .

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Angle between two vectors : $\"\"$ .

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Find angle $\"\"$ between AB and AC.

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The vector from $\"\"$ to $\"\"$ is $\"\"$ .

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The vector from $\"\"$ to $\"\"$ is $\"\"$ .

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Magnitude of A is $\"\"$ .

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Magnitude of B is $\"\"$ .

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Dot product of A and B is $\"\"$

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Angle $\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Step 2:

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Find angle $\"\"$ between AB and BC.

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The vector from $\"\"$ to $\"\"$ is $\"\"$ .

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The vector from $\"\"$ to $\"\"$ is $\"\"$ .

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Magnitude of A is $\"\"$ .

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Magnitude of B is $\"\"$ .

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Dot product of A and B is $\"\"$

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Angle $\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Step 3:

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Properties of triangle : Sum of all triangle is $\"\"$

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$\"\"$

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Solutions:

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Interior angle of triangle are $\"\"$ , $\"\"$ and $\"\"$ .