No 1 dong tolonggg pleaseeeee!!!

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∆ABC
BD² = AD × DC
BD = √(10 × 4)
BD = 2√10 cm

AB² = AD × AC = 10 × 14
AB = √140 = 2√35 cm

BC² = DC × AC = 4 × 14 = 56 cm
BC = √56 = 2√14 cm