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determiner-les-elements-demandes-dans-le-graphe-




Question Number 177769 by a.lgnaoui last updated on 08/Oct/22
determiner les elements demandes  dans le graphe
determinerleselementsdemandesdanslegraphe
Commented by a.lgnaoui last updated on 08/Oct/22
Commented by a.lgnaoui last updated on 09/Oct/22
∡ADB=180−(65+70)=45  ∡BDC=45    ⇒∡ADC=90  Donc   △ADC triangle rectangle  doonc  AC  passe par centre du cercle  AC=diametre   ACB  aussi triangle rectangle  donc  ∡DBC=90−70=20  Donc ∡ BCD=180−(45+20)=115
ADB=180(65+70)=45BDC=45ADC=90DoncADCtrianglerectangledooncACpasseparcentreducercleAC=diametreACBaussitrianglerectangledoncDBC=9070=20DoncBCD=180(45+20)=115
Answered by Ar Brandon last updated on 08/Oct/22
ΔOAB ≡ ΔOCD   ⇒∠OCD=∠OBA=70°  ⇒∠OAB=∠ODC=45°  ⇒∠OAD=65°−∠OAB=20°  ⇒∠AOB=180°−70°−45°=65°  ⇒∠BOC=180°−∠AOB=115°  ΔOBC ≡ ΔOAD  ⇒∠OBC=∠OAD=20°  ⇒∠OCB=180°−∠BOC−∠OBC=45°  (i) ∠BCD=∠OCB+∠OCD=45°+70°=115°  (ii) ∠ADB=∠OCB=45°
ΔOABΔOCDOCD=OBA=70°OAB=ODC=45°OAD=65°OAB=20°AOB=180°70°45°=65°BOC=180°AOB=115°ΔOBCΔOADOBC=OAD=20°OCB=180°BOCOBC=45°(i)BCD=OCB+OCD=45°+70°=115°(ii)ADB=OCB=45°

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