A. 18 cmb. 15 cmc. 13 cmd. 12 cm
Penyelesaian
- Panjang EH
EH = CD
EH = 9 cm
- Panjang HF
HF / BG = CF / (CF + BF)
HF / 10 = 4 / (4 + 6)
HF / 10 = 4 / 10
HF / 10 = 2 / 5
5 HF = 2 × 10
5 HF = 20
HF = 20 ÷ 5
HF = 4 cm
- Panjang EF
EF = EH + HF
EF = 9 + 4
EF = 13 cm (C)