Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

 B C

Notes for Session 5, Part C

 Note 4 If you are working in a group, check to see if anyone used a cutting method similar to the one presented here. If so, consider using their method to launch the proof rather than the one shown here.

 Note 5 Spend a few minutes reflecting on or discussing each fact. If you are working in a group, it may help to have posters of these that everyone can refer to as they work on the proofs.

 Note 6 It's sometimes hard for people to separate this figure from the cutting activities they've just been engaged with. Make sure you're clear about how the figure was constructed; it might help to create it yourself. First, start with the triangle. Find midpoints D and E and connect them. Then extend that segment to twice its length. Recall what we know: AD = DC (D is a midpoint); BE = EC (E is a midpoint); DE = EF (we made the figure that way); angle DEF is 180° (we made it a straight line). That's all we know.

 Note 7 You may have already made a conjecture about this situation in the Take It Further section of Session 4. Now you have the tools to actually prove it.