Question

ABCD trapez , AB paralel CD, AD= 8cm, DC=6 cm, m(B)=45°. Sa se afle AB. Please, ajutoor!!!

Answer 1

Fie CE perpendicular pe AB=> m(E)=90°

ADCE

m(A)=90°

m(B)=90°

m(E)=90°   => din toate patru rezulta => ADCE-dreptunghi=> [AD]≡[EC]

                                                                                                   AD=8 cm => din amandoua rezulta=> EC= 8 cm

                                                                 ADCE-dreptunghi=> [AE]≡[BC]

                                                                                                    DC=6 cm=> din amandoua rezulta=> AE= 6 cm

  ΔCEB

m(E)=90°

m(B)=45° => din toate trei rezulta => ΔCEB-isoscel=> (CE)≡(EB)

                                                                                         CE= 8 cm=> din amandoua rezulta => EB= 8 cm.

AB=AE+EB

AB=6+8=14 cm

  Sper ca te-am ajutat!