Question 100
A quadrilateral $ABCD$ that satisfies $AB = 5$, $BC = 7$, $CD = 6$ is given. And $AC$ and $BD$ are perpendicular to each other. Find the length of $DA$.
MathNet 2007-part-02 — 187 problems (EN–VI) Question 100
Math Olympiad Vault · MathNet 2007-part-02 — 187 problems (EN–VI)