Question Number 103672 by  M±th+et+s last updated on 16/Jul/20

Commented by M±th+et+s last updated on 16/Jul/20

if  AD+AC=BC  and  AB+BD=AC    find ∠ ABC

Commented bysom(math1967) last updated on 16/Jul/20

If ABC is triangle then how  AB+BC=AC ?

Commented by M±th+et+s last updated on 16/Jul/20

sorry sir its typo   thank you for your comment

Answered by Worm_Tail last updated on 16/Jul/20

  AC^2 =BC^2 +BA^2 −2(BC)(BA)cos(AB^� C)  cosine  rule    (AB+BC)^2 =BC^2 +BA^2 −2(BC)(BA)cos(AB^� C)  given    AB^2 +2(AB)(BC)+BC^2 =BC^2 +BA^2 −2(BC)(BA)cos(AB^� C)     2(AB)(BC)=−2(BC)(BA)cos(AB^� C)     −1=cos(AB^� C) ⇒AB^� C=180°