LET’S TRY ONE
Adjacent angles form a line. One is 65°. What is the other?
115
180 − 65 = 115 degrees.
Learning steps & teaching tips
Use the 180-degree sum of adjacent angles on a straight line.
- Confirm the diagram or description says the angles form a straight line.
- Work through the example. Explain how its evidence supports the answer.
- Try a new question; use the explanation to check your thinking.
Try it together
Write or draw your own example with different numbers. Solve it, then ask a partner to check the method as well as the answer.
Confirm the diagram or description says the angles form a straight line.