Question

Only the lengths of sides are needed to calculate the area of a composite figure ......true or faslse

Answer 1

so a composite figure is say, a square with a triangle on top.
Now, you can find the area of a triangle from the side lengths
But you gotta know some tricks, like Heron's formula.

In, any polygon (not necessarily regular) can be broken up into triangles. It may be possible to make a figure with all the side lengths and have it impossible to calculate the areas (b/c some angles are missing) not sure about that.