WEBVTT
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Determine whether the following is true or false: the vertices of a triangle determine a plane.
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So let’s consider three points, the vertices of a triangle, which we’ll call 𝐴, 𝐵, and 𝐶.
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As these points form a triangle, this means that all three of them don’t lie on the same straight line.
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They are noncolinear.
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One of the geometric postulates tells us that through any three noncolinear points, there is exactly one plane.
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The word exactly is key here.
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There is only one unique plane that contains all three points.
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Therefore, the statement that the vertices of a triangle determine a plane is true.