Mathematics for IGCSE & O level - Geometrical Constructions (Section 1 - No. 45)
When measuring an angle, which scale should you use?
The inner scale
The outer scale
The scale that starts at zero on the same side as one of the arms
Either inner or outer scale
Forklaring
The zero line of the protractor should align with one arm, and the correct scale should be used based on that alignment.