Question 980779: The position vector of vertice of a triangle are:(-1,2,3),(4,3,5) and (3,-2,7).find the area of the triagle.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! The position vector of vertice of a triangle are:(-1,2,3),(4,3,5) and (3,-2,7).find the area of the triagle.
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Label the points A:(-1,2,3), B(4,3,5) and C(3,-2,7)
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Vector AB = (5,1,2)
Vector AC = (4,-4,4)
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Find the cross product of AB and AC.
The magnitude of the cross product is the area of the parallelogram the 2 vectors form.
The area of the triangle is 1/2 of that.
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