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2013-06-13T14:34:26+02:00

Bonjour

Aire ABCD = 60² = 3600 

Aire AEFG = 40(60-x) 

Aire AEFG = 1/4 * Aire ABCD

40(60-x) = 1/4  * 3600

2400 - 40x = 900

40x = 2400 - 900

x = 150/4 

x = 37.5 cm