tlg bagi yg tau no.15 mohon bgt mau dikumpul bsk

BD = AC = √(AB² + BC²) = √(320 + 80) = 20 cm

AB × BC = BD × AE
8√5 × 4√5 = 20 × AE
AE = 8 cm

DE = FB = BC²/BD = 80/20 = 4

EF = BD - 2 DE = 20 - 8 = 12 cm