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jmc

geometry junior

Problem

The area of polygon , in square units, is
problem
(A)
(B)
(C)
(D)
Solution
Obviously, there are no formulas to find the area of such a messed up shape, but we do recognize some shapes we do know how to find the area of. If we continue segment until it reaches the right side at , we create two rectangles - one on the top and one on the bottom. We know how to find the area of a rectangle, and we're given the sides! We can easily find that the area of is . For the rectangle on the bottom, we do know the length of one of its sides, but we don't know the other. Note that , and , so we must have The area of the bottom rectangle is then Finally, we just add the areas of the rectangles together to get .
Final answer
C