**In class**we worked on a set of proofs in groups and put the proofs up on the board. I have attached pictures of the proofs from period 3 if you would like to see some in progress work.

**Components of a good proof**

- Clear question or statement to be proved

- Multiple well labeled, helpful diagrams. Especially useful when isolating an important triangle out of a figure in which many triangles overlap.
- Every statement is supported by a reason (and also proof indicates if a reason follows from some other statement)
- The proof has a logical structure in which there are no gaps in reasoning, each statement follows from the previous statements or stands on its own.
- The proof ends with the statement we desired to prove at the outset.

**Assignment: **4.6 on p. 231: complete 1-12 (you may skip the two problems your group worked on together)

**Pictures of student's proofs**.