00:01
This problem says that quadrilateral abcd is a parallelogram.
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If both pairs of opposite sides are congruent, show that quadrilateral abcd is a parallelogram by finding the lengths of the opposite side pairs.
00:11
And we're given the lengths of all four of our sides, but we're only actually given the length of one.
00:16
We're told that ab is equal to 21, but everything else is in terms of a variable.
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D .c is given to us at 3x.
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And then ad is given to us as y plus 7.
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And our last segment bc of our parallelogram is 2y.
00:31
So what we are asked to do is find the two links of the side links or the sides that are pairs to make this a parallelogram.
00:39
So if this is a parallelogram, that means side a, b, that's opposite of d .c is congruent to each other.
00:44
And side a, d, and side b, c, opposite of each other are also congruent...