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2009 AMC 12B Question 16

AMC12 · 2009 AMC 12B

Question 16

Trapezoid $ABCD$ has $AD \parallel BC,$ $BD = 1,$ $\angle DBA = 23^\circ,$ and $\angle BDC = 46^\circ.$ The ratio $BC : AD$ is $9 : 5.$ What is $CD?$
  1. $\dfrac{7}{9}$
  2. $\dfrac{4}{5}$
  3. $\dfrac{13}{15}$
  4. $\dfrac{8}{9}$
  5. $\dfrac{14}{15}$