ShmoopTube

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Here’s an unshmoopy question you’ll find on an exam somewhere in life...

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Which of the following best describes the transformation of triangle RST to triangle

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R'S'T', as shown in the graph below?

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And here are the potential answers...

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OK, this is kind of a vocabulary test more than anything,

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and we have a few 5 dollar words we have to define.

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Dilation is when the measurements of a shape expand.

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Dilation is when the measurements of a shape expand.

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Reflection is when a shape is reflected across an axis…

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…and Rotation is when a shape is rotated on a graph.

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Now let’s look at each of the options and see how they stack up…

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It’s easy to see that dilation is… not the droid we’re looking for.

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The triangle certainly does look reflected…

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… but not across the y-axis.

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That would look something like this…

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But choice C supposes we reflect it across

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the x-axis and then move it 6 units to the right…

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…and that looks about right.

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Just to cover all our bases, let’s take a gander at D.

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This triangle COULD be rotated…

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… except that if we’re rotating about the origin, R prime would be at 2,0 and not

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4,0, as shown on the graph. So our answer is indeed C.

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