Tolong nomor 50-52, kalau bisa cepet ya

50)
AB² + BC² = AC²
AB² + 15² = 17²
AB² + 225 = 289
AB² = 64
AB = √64 = 8 cm

luas ∆ABC = luas ∆ ABC
AB × BC × ½ = AC × BE × ½
AB × BC = AC × BE
8 × 15 = 17 × BE
17 × BE = 120
BE = 120/7

jadi, panjang BE = 120 / 17 cm

51)
< ABC + < ACB + < BAC = 180
(5x + 9) + (9x + 3) + 7x = 180
21x + 12 = 180
21x = 168
x = 8

besar < ACB = 9x + 3 = 9(8) + 3 = 72 + 3 = 75°

jadi, besar sudut ACB 75°

52) luas ∆ ACD = a × t × ½
= AB × CD × ½
= 12 × 11 × ½
= 66

jadi, luas ∆ACD = 66 cm²