What term describes the three-dimensional volume of an object?

• A. Line
• B. Color
• C. Form
• D. Texture

Answer: (C)

Form is the quality that defines an object's three-dimensional volume—the height, width, and depth that give it mass and presence in space. This is what makes a chair feel solid, a vase seem like it occupies space, or a sculpture project into a room. It’s different from line, which is a mark or edge with length but no real volume; color, which concerns hue and value and affects mood rather than physical bulk; and texture, which describes how a surface feels or appears to feel and adds surface interest without changing the object's volume. In interior design, understanding form helps you read and control spatial relationships, guiding decisions about scale, balance, and how light interacts with objects in a room.