M2.5.3 For the adult
Right angles and turns
How can I tell if a corner is a right angle?
What this chapter teaches
An angle is how much one line turns away from another, not how long its lines are. A right angle is a square corner, and a quarter turn makes one.
Three questions to ask
There is no one right wording. Listen for the idea.
- How would you check whether a corner is a right angle?
- Two right angles have lines of different lengths. Are they the same size, and how do you know?
- If you turn a quarter turn twice, which way are you facing now?
After the chapter, the learner can
- Make a right angle tester by folding paper twice
- Compare an angle with a right angle: smaller, equal or bigger
- Find lines that meet at a right angle
What they copy into their notebook
Fold paper twice to make a right angle tester. Acute is smaller than a right angle. Obtuse is bigger. The size of an angle is how much it turns.