UPSC 2015 CDS II Math Paper

Let the parallel sides of the trapezium be 5k and 7k
Area of the trapezium =

1

2

× Sum of the parallel sides × Perpendiculardistance between the parallel sides
∴

1

2

×(5k+7k)×14=336
⇒84k=365
⇒k=4
Therefore, smaller of the parallel sides =5×4=20cm