The trapezoid diagonal is 6, it divides the trapezoid into two similar triangles. Find the length of the lower base of the trapezoid if the bigger base is 12?

1 Answer
Oct 9, 2017

33 units

Explanation:

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As shown in the figures, AD and BCADandBC are the bases of the trapezoid ABCDABCD,
As ADAD is parallel to BCBC,
=> angleBCD=angleCAD=xBCD=CAD=x
Given that the diagonal ACAC divides the trapezoid into two similar triangles, namely, DeltaABC, and DeltaDCA, and as angleADC != angleABC
=> angleCAB=angleADC=y
=> (BC)/(AC)=(CA)/(DA)
=> (BC)/6 = 6/(12)
=> BC=3