D and E are two points respectively on sides AB and AC of triangle ABC such that DE is parallel to BC. If the ratio of area of triangle ADE to that of the trapezium DECB is 25:144 and BC=13 cm, then find the length of DE.
Options.
A) 12  B) 5  C) 14  D) 11  E) 15
ABC and ADE are similar triangles.   So (side of A5C/side of ADE)^2=169/25   side of A5C/side of ADE = 13/5   So the length of DE = 5   Answer - 5
<result>B</result>
D and E are two points respectively on sides AB and AC of triangle ABC such that DE is parallel to BC. If the ratio of area of triangle ADE to that of the trapezium DECB is 25:144 and BC=13 cm, then find the length of DE.