Thursday, Dec 1st

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.

Inline image 2

Inline image 4

Inline image 5

Inline image 7

Inline image 9

Inline image 3