Credit for the Bad parts, too. |

Take this problem, from the Semester Exam:

Triangle ABC is congruent to triangle DEF. In triangle ABC, side AB measures 9, side BC measures 3x+18, and side CA measures 7. In triangle DEF, side DE measures 9, side EF measures 2x+26, and side FD measures 7. What equation would help you to solve for the side length of BC and EF? Explain your reasoning using complete sentences. (10 points)At first blush, you say "They're congruent. BC is congruent to EF, so 2x+26=3x+18. Done."

What's the big deal?

Solve it.

Pretty easy ... x = 8. So the sides of a triangle are 9, 7, and 42. Shit.

Any student who takes that obvious next step, and thinks for more than a second about a different topic just studied, i.e. comparing sides of a triangle and scissors theorem, is now convinced he's done something wrong.

It's not Psuedocontext, it's just wrong.

They are so rushing the Common Core without time to tweak it an get it right.

ReplyDelete"and"

ReplyDeleteHate hate hate bad problems (and often pseudo context). Which is not to claim that you would never find this bad of a problem in a textbook. That happens too.

ReplyDeleteThese people who wrote this problem clearly haven't got a clue. The whole idea of forcing an algebraic problem onto a geometrical situation is hopelessly wrong headed. The other way round, ie finding an algebraic representation of a geometrical problem - that IS math.

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