Răspuns:
Explicație pas cu pas:
Ex8
A(-6;3), B(2;9), C(4;-4), D(-2;-5).
[tex]AB=\sqrt{(-6-2)^{2}+(3-9)^{2}}=\sqrt{64+36}=10.\\AC=\sqrt{(-6-4)^{2}+(3-(-4))^{2}}=\sqrt{100+49}=\sqrt{149} .\\AD=\sqrt{(-6-(-2))^{2}+(3-(-5))^{2}}=\sqrt{16+64}=\sqrt{80} =\sqrt{16*5} =4\sqrt{5} .\\BC=\sqrt{(2-4)^{2}+(9-(-4))^{2}}=\sqrt{4+169}=\sqrt{173} .\\BD=\sqrt{(2-(-2))^{2}+(9-(-5))^{2}}=\sqrt{16+196}=\sqrt{212} =\sqrt{4*53}=2\sqrt{53}. \\CD=\sqrt{(4-(-2))^{2}+(-4-(-5))^{2}}=\sqrt{36+1}=\sqrt{37} ..[/tex]
