Răspuns:
Explicație pas cu pas:
Notam PC=x
[tex]A_{AMN}=\frac{AM\cdot AN}{2} =3cm^{2}[/tex]
[tex]A_{NDP}=\frac{ND\cdot DP}{2} =\frac{7(10-x)}{2}[/tex]
ND=10-3=7
MB=10-2=8
[tex]A_{CPMB}=\frac{(PC+MB)BC}{2} =\frac{(x+8)\cdot 10}{2} =5(x+8)[/tex]
[tex]A_{ABCD}=l^{2} =100cm^{2}[/tex]
[tex]A_{MNP}=A_{ABCD}-A_{AMN}-A_{NDP}-A_{CPMB}[/tex]
[tex]16=100-3-\frac{7(10-x)}{2} -\frac{10(x+8)}{2}[/tex]
32=194-70+7x-10x-80
32=124-3x-80
3x=44-32
3x=12
x=4 PC=4
