Răspuns:
Explicație pas cu pas:
P=2L+2l=28 cm
L=4k
l=3k
inlocuim si obtinem
2×4k+2×3k=28
14k=28
k=2⇒ L=8 si l=6
adica AB=8 si BC=6
A=L×l=8×6=48 cm²
AM=6 cm ⇒MB=8-6=2 cm
[tex]A_{MBC} =\frac{MB\cdot BC}{2} =\frac{2\cdot 6 }{2} =6 \\A_{AMD} =\frac{AD \cdot AM}{2} =\frac{6\cdot8}{2}=24[/tex]
[tex]A_{DMC}=A_{ABCD}-A_{AMD}-A_{MBC} =48-24-6=18[/tex]
