Description: The area of a quadrilateral with two sides which are parallel to the y-axis in ( RR X. RR ) is its width multiplied by the average height of its higher edge minus the average height of its lower edge. Co-author TA. (Contributed by Jon Pennant, 31-May-2019)
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Hypotheses | areaquad.1 | |
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areaquad.2 | |
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Assertion | areaquad | |