Explicație pas cu pas:
A(-3;4), B(-3;0), C(5; -3), D(5; 0)
a)
b)
[tex]AB = \sqrt{ {( - 3 - ( - 3))}^{2} + {(4 - 0)}^{2} } = \sqrt{0 + 16} = 4[/tex]
[tex]BC = \sqrt{ {( - 3 - 5)}^{2} + (0 - ( - 3))^{2}} = \sqrt{64 + 9} = \sqrt{73} [/tex]
[tex]CD = \sqrt{ {(5 - 5)}^{2} + {( - 3 - 0)}^{2} } = \sqrt{0 + 9} = 3[/tex]
[tex]AD = \sqrt{ {( - 3 - 5)}^{2} + {(4 - 0)}^{2}} = \sqrt{64 + 16} = \sqrt{80} = 4 \sqrt{5} [/tex]
[tex]Perimetrul(ABCD) = AB + BC + CD + AD = 4 + \sqrt{73} + 3 + 4 \sqrt{5} = 7 + \sqrt{5} + \sqrt{73} [/tex]
c)
[tex]BD = \sqrt{ {( - 3 - 5)}^{2} + {(0 - 0)}^{2} } = \sqrt{64 + 0} = 8[/tex]
[tex]Aria(ABCD) = \frac{(AB+DC) \times BD}{2} = \frac{(4 + 3) \times 8}{2} = 7 \times 4 = 28[/tex]