Measure from the vertex
Put the centre of the protractor exactly on the corner of the angle.
If the centre is not on the vertex, the reading will be wrong.
Year 5
Draw given angles, and measure them in degrees
Measure and draw angles in degrees using a protractor carefully.
Lesson overview
Geometry - properties of shape
A protractor helps us measure or draw the amount of turn between two lines. We place the centre on the vertex, line up the baseline with one arm, and then read the correct scale to find or draw the angle.
Line up one arm
One arm of the angle should sit on the zero line before you read the other arm.
read here
Choose the scale that starts at zero on the arm you lined up.
Draw the angle
Mark the degree point first, then use a ruler to draw the second arm.
This keeps the angle neat and accurate.
Worked example
Draw an angle of 70 degrees.
- Draw one straight baseline.
- Place the protractor centre on the endpoint.
- Find 70 degrees on the correct scale and make a small mark.
- Draw a second line from the vertex through the mark.
Round 1: Learn it
Focus on the vertex, the zero line and the correct scale.
Finish this round to unlock Round 2: Show you know it.
Question 1
Where should the centre mark of the protractor go?
Question 2
Which line should be lined up with zero degrees first?
Question 3
A right angle measures how many degrees?
Question 4
After marking the degree point, what should you do next when drawing an angle?
Question 5
Which tool is used to measure angles in degrees?
Common mistakes
Watch for these as you work through the lesson.
- Putting the centre of the protractor away from the vertex.
- Reading the wrong scale on the protractor.
- Forgetting to line up one arm with zero degrees.
Related topics
These ideas connect closely to this lesson.
- Know angles are measured in degrees, estimate and compare acute, obtuse and reflex angles.
- Identify angles at a point and one whole turn, on a straight line and at a point on a line, and use these facts to find missing angles.