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Cel mai inteligent răspuns!
2014-04-21T17:04:52+03:00
Daca ∧B=60⇒in ΔCAB,∧CAB=30
∧CAD=60 si DCA=30
cateta care se opune unghiului de 30 este 1/2 din ipotenuza
AC=AD.2=18.2=36
sin 60=AC/AB⇒√3/2= 36/AB⇒AB=24√3 
aplicam th catetei in ΔACB⇒
AC²=AM.AB(unde M piciorul perpendicularei din C pe AB)
36²=AM.24√3⇒AM=18√3
MB=24√3-18√3=6√3
din ΔCMB CB²=CM²+MB²⇒CB=324+108⇒CB=12√3
P= 18+18√3+12√3+24√3=18+54√3
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  • Utilizator Brainly
2014-04-21T17:10:56+03:00
 Δ ADCsin de 30 de grade = AD/AC ⇒ 1/2= 18/AC ⇒ AC= 2*18 rezulta AC= 36 ; 
cos 30 = DC/AC⇒√3/2= DC/36⇒DC=36√3/2⇒DC=18√3
ΔABC sin 60=DC/AB⇒√3/2=36/AB⇒AB=36*2/√3⇒AB=72/√3
cos60=BC/AB⇒1/2=BC/72/√3⇒BC=72/√3/2⇒BC=144/√3
P= AB+BC+CD+AD
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