# Raising the flag

Geometry Level 3

Figure above shows two right triangles $$DAB$$ and $$ABC$$ with right angles at $$A$$ and $$B$$ respectively. With $$E$$ is the point of intersection between the straight lines $$BD$$ and $$AC$$. If we drop a straight line from $$E$$ that is perpendicular to the base $$AB$$ and intersect at $$AB$$ at point $$F$$, find the distance $$EF$$ in $$\text{cm}$$.

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