tolong batuin aku jawab no 54 -56 dokpng kak butuh banget nih.....

54. BD² = AB² + AD²
BD² = 15² +8²
BD = 17
keliling = AB + BD + AD = 15 + 17 + 8 = 40 cm

56. Luas Δ ABC = 1/2 (alas )(tinggi)
L = 1/2 (AB)(CD)
L = 1/2 (16+5)(12)
L = 6(21)
L = 126 cm²