Réponses

2014-02-06T18:35:17+01:00
JK = FG = BC =  6 cm
EI/EF = EI/EA => EI = 8 x 12/15 = 32/5
IJ = V(EI² + EJ²) = V(1024/25 + 144) = 13,6 cm
aire du rectangle = 13,6 x 6 = 31,6 cm² 
Tan JIK = JK/IJ =  6/13,6 = 0,44.... => JIK = 23,8 soit 24°