What’s a foot long and slippery?

What are the two ways in which you can identify forms? cones and spheres are examples of (dark/artifical/geometric) forms, whereas mountains and trees are (natural/organic/light) forms.

What convetion did chardin and delacroix use in the painting grace before meal and liberty leading the people to give the artworks a sense of harmony and stability?

What year was the original wizard of oz movie released?