# Teacher Notes

### Why use this resource?

Here are some videos that show the stages in using Pythagoras for finding the distance between two points. This might be useful when students are revising this idea (or indeed meeting it for the first time).

### Possible approach

Students could use these videos in their own time to ensure they are happy with the technique. If used in class, perhaps show the first video to each question, then asks students to complete the rest. The final video could then be watched to check the method.

### Key questions

• How can we generalise this idea for the distance between any two points?

### Possible support

Encourage students to look back at the two examples they have completed in order to generalise for any two points.

### Possible extension

Would this work in threee dimensions $(x_1,y_1,z_1)$ and $(x_2,y_2,z_2)$ ? Explain your reasoning.