View Proposal #224
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| ID | 224 |
|---|---|
| First Name | Christian |
| Last Name | Roettger |
| Institution | Iowa State University |
| Speaker Category | faculty |
| Title of Talk | Proofs in elementary geometry - what IS the sum of angles in a triangle? |
| Abstract | One textbook for future teachers gives no less than four 'arguments' for this theorem. It is not claimed that they are proofs, and indeed they are not (all involve some circular reasoning). But the difference between such arguments and proofs is never made clear. We'll discover the flaws in the logic here, which are not obvious at all. Then we'll look at a number of examples from standard elementary geometry - some rock-solid one-line proofs, some examples where we all skip the proof and eyeball it, and finally an example which shows how 'eyeballing it' can lead to a 'proof' of 64=65. |
| Subject area(s) | geometry, teacher education, proof |
| Suitable for undergraduates? | Yes |
| Day Preference | |
| Computer Needed? | N |
| Bringing a laptop? | Y |
| Overhead Needed? | N |
| Software requests | |
| Special Needs | |
| Date Submitted | 3/15/2008 |
| Year | 2008 |