Răspuns:
23 a) [tex]A_{ABCD} = L*l = > A_{ABCD}= 8*6= > A_{ABCD}=48 cm^{2}[/tex]
b) T Pitagora [tex]DB^{2} =AB^{2} +AD^{2} = > DB^{2}=8^{2}+6^{2}= > DB^{2}=64+36= > DB^{2}=100= > \\ DB=\sqrt{100} = > DB=10[/tex]
diagonalele in dreptunghi sunt egale si se injumatatesc
[tex]AO=OB=\frac{DB}{2} = \frac{10}{2} =5 cm\\P_{AOB}=AO+OB+AB=5+5+8=18 cm[/tex]
24 12 triunghiuri
25 [tex]M_{g} =\sqrt{(6-2\sqrt{5})*(6+2\sqrt{5}) }=\sqrt{36-20}=\sqrt{16}=4[/tex]
Explicație pas cu pas:
