What is the purpose of a scale on a drawing?

• A. Increases all dimensions by a constant factor
• B. Keeps dimensions constant
• C. Reduces or enlarges dimensions proportionally
• D. Indicates only lengths in inches

Answer: (C)

Understanding how a scale works on a drawing is about how size is represented accurately on paper. A drawing scale applies a single factor to all dimensions, so every measurement is multiplied (or divided) by the same amount. This lets you shrink or enlarge the whole object while preserving the true proportions between every feature. That’s why the best choice says dimensions can be reduced or enlarged proportionally—the scale keeps the relationships intact no matter the direction.

If you use a 1:4 scale, for example, every drawing inch stands for 4 real inches, so the drawing fits on the page but still shows the true size relationships. The other ideas aren’t the purpose: a scale doesn’t keep dimensions constant, and it isn’t limited to lengths in inches—the scale is about proportional change and consistent ratios, not a fixed size or a unit-only rule.