Final answer:
Predefined contours work best for simple geometries when estimating measurements.
Step-by-step explanation:
When estimating measurements, predefined contours work best for simple geometries. Predefined contours provide a reference point for estimating dimensions, which makes it easier to estimate measurements with more accuracy. For example, if you have a predefined contour for a square, you can compare the dimensions of a complex shape to that square to estimate its measurements.