Question

ratio of aera of trapezium DECB by aera of triangle ABC​

Answer 1

Answer:

∆ ADE is similar to ∆ ABC (AAA crieterian)

So, ar(ADE)/ar(ABC) =

sq.of(AD)/sq of AB = (2x2)/(5x5)

= 4/25

Now let ar(ADE) = 4x

ar(ABC) = 25x

so, ar(trapezium DECB) = 25x - 4x

= 21x

ar(trapezium DECB)/ar(ABC)

= 21x/25x = 21/25

Hence the required ratio 21:25 (Ans)