CAYLEY 2005 Problem 24

The base of a triangular piece of paper ABC is 12\:cm long. The paper is folded down over the base, with the crease DE parallel to the base of the paper. The area of the triangle that projects below the base is 16\% that of the area of the triangle ABC. The length of DE, in cm, is

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Answer Choices
A. 9.6
B. 8.4
C. 7.2
D. 4.8
E. 6.96