The proof that the diagram is a square is that; D: slopes are perpendicular where the sides meet
How to Prove a quadrilateral is a Square?
We know that a square is a quadrilateral that has 4 sides. Now, the 4 sides of a square are all equal and at right angles.
Since all sides of the square are equal, then it means that 2 consecutive sides must be perpendicular to each other. Thus, this means that the slope of 2 consecutive sides must be perpendicular to each other.
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