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in trapezoid abcd, bc = ef = 6, af = de = 3, and
ab = cd = 5. if the area of a trapezoid is given by
then which of the following is the area of trapezoid abcd?
title
pythagorean trapezoid area
your result
correct
difficulty
medium
your pace
0:02
others' pace
1:34
video explanation
text explanation
we have most of the measurements, but we need the height. look at triangle abf, the side triangle on the right. we know that ab = 5 and af = 3, so this has sides {3, _, 5}. since abf is a right triangle, it must be a 3-4-5 triangle. for this test, you absolutely have to recognize the 3-4-5 triangle, because it almost guaranteed to come up at least once on the test. here, in triangle abf, the missing side, bf = 4. that's the height.
the two bases are bc = 6 and ad = 3 + 6 + 3 = 12
answer = (c)
related lessons
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