Question 3 Diagonals AC and BD of a trapezium ABCD with AB || DC intersect each other at the point O. Using a similarity criterion for two triangles, show that AOOC=OBOD.
Open in App
Solution
In ΔDOC and ΔBOA, ∠CDO=∠ABO [Alternate interior angles as AB || CD] ∠DCO=∠BAO [Alternate interior angles as AB || CD] ∠DOC=∠BOA [Vertically opposite angles] ∴ΔDOC∼ΔBOA [AAA similarity criterion] ∴DOBO=OCOA [Corresponding sides are proportional] ⇒OAOC=OBOD