Question

Answer 1

\(\Delta ABC\sim\Delta DEF\)\(\Rightarrow\dfrac{AB}{DE}=\dfrac{BC}{EF}\)

\(\Leftrightarrow AB=\dfrac{BC.DE}{EF}=\dfrac{12.12}{9}=16\)

Ý B

Answer 2

Tam giác ABC đồng dạng với tam giác DEF nên : 

\(\dfrac{AB}{DE}=\dfrac{BC}{EF}\)

\(\Rightarrow AB=\dfrac{12\cdot12}{9}=16\left(cm\right)\)

Answer 3

vì \(\Delta ABC\sim\Delta\)DEF=>\(\dfrac{AB}{DE}=\dfrac{BC}{EF}\)\(< =>AB=\dfrac{BC.DE}{EF}=\dfrac{12.12}{9}=16cm\)

=> đáp án :B