OpenOlympiad
Concept 4 of 8Foundation
Video

Measuring angles with a protractor

Steps:

  1. Place protractor's centre on the vertex.
  2. Align baseline with one arm of the angle.
  3. Read the scale where the other arm crosses.

Most protractors have TWO scales (0° from left and 0° from right) — choose the scale that starts at 0° on your aligned arm.

Example
Your angle's arm aligns with 0° on the inner scale. Other arm crosses at 125° on inner scale → angle is 125°.
💡 Tip:If your answer looks obtuse but protractor says acute (or vice versa), you read the wrong scale.
Prefer a video? Open YouTube search for “how to use a protractor class 6

🎯 Try it!

5 questions to check what you just read.

0 / 5
  1. Q1.Centre of the protractor goes on the:
  2. Q2.If one arm lines up at 0° on inner scale, read the other arm on:
  3. Q3.A protractor typically shows angles from 0° to:
  4. Q4.To measure a reflex angle (>180°), use:
  5. Q5.If you read an obtuse angle as acute, you likely: