Bantuin dong, buat UKK nanti.

diketahui:
AB =DC = HG = EF = 9 cm
BC = AD = EH = FG = 12 cm
AE = FB = GC = HD = 20 cm

ditanya:
keliling ∆ ACG =?

dijawab:
AB² + BC² = AC²
9² + 12² = AC²
81 + 144 = AC²
AC² = 225
AC = √225
AC = 15 cm

AC² + GC² = AG²
15² + 20² = AG²
225 + 400 = AG²
AG² = 625
AG= √625
AG = 25 cm

keliling ∆ ACG = AC + AG + GC = 15 + 25 + 20 = 60 cm

jadi, keliling ∆ ACG adalah 60 cm (A)