Hmmm, I couldn't find a geometric way to solve this within the 1 minute I looked at this problem. I am very inpatient!
So let us use coordinates!
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Find ST
ST = 40/3 by simple algebra I think you can do at your skill level judging by the difficult of this problem.
Let QR = a
Slope of PT: −403a
Y-intercept of PT: 20
Equation: y=−403ax+20
Slope of QS: (20/a)
Y intercept of QS: 0
Equation: y=20ax
Substitute
−403ax+20=20ax
20=1003ax
20a=100x3
60a=100x
3a=5x
53x=a
Interpret this:
x is the x-coordinate of the solution of we solved for the location of the intercept at point U. That means x is the length of QV. We know a is the length of QR.
That means QV is three-fifths the length of QR.
We know that QUV is similar to QSR by AA similarity through a series of proofs.
Since we know the proportion of the sides, we can solve for UV:
Solve:
20 * (3/5) = 12
Ta-da! Mathz! 