ΔABC dreptunghic isoscel in varful A, A = 90,
Aabc = 18cm^2
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perimetrul ?
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Aabc = AB*AC/2 = (AB^2)/2 = 18cm^2 => AB^2 = 36cm^2 => AB = 6cm
AB = AC, A = 90 => BC = ?
B = C = 45 => BC = 2*AB*cos45 = 2*6*0.707 = 8.484
BC = 8.484cm
Pabc = 2*AB + BC = 12 + 8.484 = 20.484
