Mathématiques

Question

help si je fais pas j'ai colle ⛔⛔⛔
help si je fais pas j'ai colle ⛔⛔⛔

1 Réponse

  • Exercice 2 :
    a) AC/AN = AB/AM = BC/MN
    3/AN = AB/4,5 = 2/6
    3/AN = 2/6
    AN = 3 x 6 / 2 = 9 cm
    AB/4,5 = 2/6
    AB = 4,5 x 2 / 6 = 1,5 cm
    b) CS/CB = CT/CA = ST/BA
    5/13 = CT/6,5 = 3/BA
    5/13 = CT/6,5
    CT = 6,5 x 5 / 13 = 2,5 cm
    5/13 = 3/BA
    BA = 13x3/5 = 7,8 cm
    c) AP/AB = AM/AC = PM/BC
    AC = AMxAB/AP = 5x6/4 = 7,5 cm
    BC = PMxAB/AP = 3x6/4 = 4,5 cm
    d) IL/IJ = IM/IK = LM/JK
    IK = IMxIJ/IL = 5x10/8 = 6,25 cm
    MK = IK-IM = 6,25 - 5 = 1,25 cm
    LM = ILxJK/IJ = 8x7/10  = 5,6 cm

    Exercice 3 :
    1) (IJ)//(AP)
    D'après Thalès :
    IJ/AP = DI/DP = DJ/DA
    IJ/32 = 15/20 = DJ/45
    IJ = 32 x 15 / 20 = 24 mm
    DJ = 45 x 15 / 20 = 33,75 mm
    2) (JK)//(DR)
    D'après Thalès :
    AJ/AD = JK/DR
    11,25/45 = JK/48
    JK = 48x11,25 / 45 = 12 mm
    IK = IJ + JK = 24 + 12 = 36 mm