5 (a) In figure () given below, DEII BCtriangle0) In figure (il) given

1.	5 (a) In figure () given below, DEII BCtriangle0) In figure (il) given below, AB \| DE and BD \|\| EF. Prove that DC2CF x AC.(0
Answer» InΔABC, we have CD/DA = CE/EB as AB \|\| DEinΔCDB, we have CF/FD = CE/EB as EF \|\| BD hence we get CD/DA = CF/FD=>Reciprocals: DA/CD = FD /CF=> Add 1 on bothsides: AC /CD = DC/CF => DC^2 = CF * AC thanks

5 (a) In figure () given below, DEII BCtriangle0) In figure (il) given below, AB | DE and BD || EF. Prove that DC2CF x AC.(0

Answer»

InΔABC, we have CD/DA = CE/EB as AB || DEinΔCDB, we have CF/FD = CE/EB as EF || BD

hence we get CD/DA = CF/FD=>Reciprocals: DA/CD = FD /CF=> Add 1 on bothsides: AC /CD = DC/CF

=> DC^2 = CF * AC

thanks