Answer:
Sand Dune Landforms
Sand dunes (both active and stabilized by vegetation) can be found along beaches, and in arid or semi-arid regions. Dunes are mounds of loose sand created by wind and are the most well known aeolian features
Simple way to see it is to multiply the value opposite of the axis you're flipping it over by -1. For example the point (-5,7) would become (5,7) when reflected over the y-axis, because the point is moving from the left to the right. This means the triangle would be (1,3) (5,3) and (5,7) when reflected over the y-axis. For reflection over the x-axis it would be (-1,-3) (-5,-3) and (-5,-7) because each point is moving down.
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