tolong yang no 7 ya kak.

CD² = DE² + CE²
CD²  = 6² + 8²
CD²  = 36 + 64
CD²  = 100
CD = √100
CD = 10 cm

BC / AC = DE / DC
BC / 15 = 8 / 10
BC = 8/10 X 15
BC = 12 cm

BD = BC - DC = 12 - 10 = 2 cm

Jawaban A