2004 Fermat Problem 14

In the diagram, ABCD is a rectangle and point E lies on AB. Triangle DEC has \angle DEC = 90^\circ, DE = 3 and EC = 4. The length of AD is

\textbf{(A)}\ 2.6\quad \textbf{(B)}\ 2.4\quad \textbf{(C)}\ 2.8\quad \textbf{(D)}\ 1.8\quad \textbf{(E)}\ 3.2

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