Liceu
BC/sin A=AB/sinC=AC/sinB
sin B=sin45°=√2/2
sinC=sin30°=1/2
sin A=sin105°=sin (80°-105°)=sin75°=sin(45°+30°)= sin45°cos30°+sin30°cos45°=(√2/2)*√3/2+(1/2)*√2/2= (√6+√2)/4
BC/sinA=4=AB/(1/2) =AC/(√2/2)
⇒AB=2 si AC=2√2
Perimetru=2+2√2+√6+√2=2+3√2+√6
gimnaziu
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