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2021 AMC 10A Question 17

AMC10 · 2021 AMC 10A

Question 17

Trapezoid $ABCD$ has $\overline{AB}\parallel\overline{CD},$ $BC=CD=43,$ and $\overline{AD}\perp\overline{BD}.$ Let $O$ be the intersection of the diagonals $\overline{AC}$ and $\overline{BD},$ and let $P$ be the midpoint of $\overline{BD}.$

Given that $OP=11,$ the length of $AD$ can be written in the form $m\sqrt{n},$ where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime. What is $m+n?$
  1. $65$
  2. $132$
  3. $157$
  4. $194$
  5. $215$