<h3>
Answer: 36.4 units (choice A)</h3>
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Explanation:
Let's use the distance formula to find the distance from D to E

Note: uppercase D refers to the point, while lowercase d is the distance from D to E.
The length of segment DE is roughly 10.198 units long.
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Repeat for the distance from E to F.

Segment EF is roughly 11.1803 units long.
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Repeat for the distance from F to D.

Unlike the others, this result is exact.
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Add up the three segment lengths to get the perimeter
DE + EF + FD
10.198 + 11.1803 + 15
36.3783
The perimeter is approximately 36.3783 units which rounds to <u>36.4</u>
The answer has been confirmed with GeoGebra.