Question

ABCD- квадрат ,ВЕ-перпендикуляр к (ABC), угол ЕАВ = 45 градусов,S авсd =4 НАЙТИ : S треугольника АЕС

Answer 1

$1) AB =sqrt{S}=sqrt{4}=2 \ 2) AE =frac{AB}{cos LEAB} = frac{2cdot2}{sqrt{2}}= 2sqrt{2} \ AC = AE = 2sqrt{2} (AB = CB) \ 3) AC = sqrt{AB^2 + CB^2} = sqrt{4 + 4}=2sqrt{2} \ 4) AE = EC = CA \ S = frac{sqrt{3} AE^2}{4} = frac{sqrt{3} (2sqrt{2})^2}{4} = 2sqrt{3}$