Friday, Dec. 2 – Flow Proofs

In class we learned to create flow proofs. I have attached an example and students worked on practice. In order to be proficient, a student should be able to create a proof on their own for problems in which the diagram can be understand fairly quickly (#7 on this assignment). Highly proficient students should be able to create proofs similar to the one I attached and in cases when a clear proof would require them to see segments or shapes that are not given as well as identifying important relationships between triangles which may be overlapping etc. (some examples of this from 4.6 problem set).

Assignment: 4.7: (4-6 talk through, don't need to write anything), complete 7-13, 15


* What is the significance of the arrows in a flow proof?

* What are some different ways you could organize this flow proof into a 2-column proof?


* Arrows are used to indicate when one statement follows from another. The arrow shows the order of the logic.

* Statements could, arguably be put into many different orderings so long as no statement comes before a statement which pointed to it in the flow proof. So there are many ways to arrange these statements into a valid proof, it would be preferable to set up the statements so that one line of reasoning is presented without interruption.