<PRE><B>Question 466707</B>
find the area of the quardilateral whose coordinates are (0,0),(3,0),(0,3),(7,5)
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Label the points A to D in order (0,0),(3,0),(7,5),(0,3)
A B C D A
0 3 7 0 0
0 0 5 3 0
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Add the upward diagonal products:
0*3 + 0*7 + 5*0 + 3*0 = 0
Add the downward diagonal products:
0*0 + 3*5 + 7*3 + 0*0 = 36
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Area = (36 - 0)/2
Area = 18 sq units.</PRE>