Question

Giúp mik bài 5 với ạ

Answer 1

a, \(S_{ABCD}=12\times6=72\left(cm^2\right)\)

b,Ta có: DE=DC-EC=12-9=3(cm)

\(S_{ADE}=\dfrac{6\times3}{2}=9\left(cm^2\right)\)

\(S_{ABCE}=\dfrac{\left(12+9\right)\times6}{2}=63\left(cm^2\right)\)

\(\dfrac{S_{ADE}}{S_{ABCE}}=\dfrac{9}{63}=\dfrac{1}{7}\)

Answer 2

a, SABCD=12×6=72(cm2)

b,Ta có: DE=DC-EC=12-9=3(cm)

SABCE=(12+9)×62=63(cm2)