" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
lihat Δ ADE
∠ ADE = 30° ⇒ AE : AD = 1 : 2
AE : 10 = 1 : 2
2.AE = 10
AE = 10/2
AE = 5 cm
BF= AE = 5 cm
DC = EF
= AB - AE - BF
= 18 - 5 - 5
= 8 cm ...... jawaban : D
perhatikan sketsa di bawah ini