tolong bntu sapa ja nih pls

luas segitiga = ½ × alas × tinggi

luas ABC = ½ × AB × CD
40 = ½ × AB × 8
40 = 4 × AB
AB = 40/4 = 10 cm

luas ABF = ½ × AB × FE
= ½ × 10 × 5 = 25 cm²