Points and are located in 3-dimensional space with and . The plane of is parallel to . What is the area of ?
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Solution
2007 AMC 12B Problem 25.png
Link to graph: https://www.math3d.org/pHFSD6vRi
Let , and . Since , we could let , , and . Now to get back to we need another vertex . Now if we look at this configuration as if it was two dimensions, we would see a square missing a side if we don't draw . Now we can bend these three sides into an equilateral triangle, and the coordinates change: , , , , and . Checking for all the requirements, they are all satisfied. Now we find the area of triangle . The side lengths of this triangle are , which is an isosceles right triangle. Thus the area of it is .
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