The area of a trapezium is given to be:
[tex]A=\frac{1}{2}(a+b)h[/tex]If the two trapeziums are similar, then we have that the ratio of corresponding sides will be the ratio of the square roots of their areas.
Therefore, the ratio will be:
[tex]\frac{\sqrt{25}}{\sqrt{36}}=\frac{5}{6}[/tex]Therefore, the ratio is 5:6.