Standardized testing has killed geometry. All that’s left to do is plan the
funeral. True, geometry had been ailing
for some time and was too weak to put up a fight. Still, theoretical mathematicians should
pause for a moment of silence and then figure out what to do next.

The objective of geometry was never understood by most
modern folks. They tended to dismiss it
as the study of “shapes” and to wonder why it was included in the
curriculum. But geometry was never about
shapes. Shapes were merely intended as
the vehicle for making deductive reasoning more accessible to students. Students tended to find formal proof to be
very challenging, and as the self-esteem movement grew and grade inflation ran
amuck, math teachers were under more pressure to gloss over the proofs that
made the subject so difficult.
Eventually, many, if not most, high school students went off to college
without ever having done a formal mathematical proof.

Still, geometry problems tended to involve informal deductive
reasoning: “I know these two lines are
parallel, therefore these angles must be congruent. If that’s true, then this thing is a
parallelogram and these two line segments are congruent.” In addition, geometry continued to be a class
where you had to be careful and precise about how you talked about
something. Definitions were
important. Leave out a phrase, and
everything changes.

The problem is that formal deductive reasoning can be
difficult to test. Informal deductive
reasoning is easier to test, but requires a great deal of background knowledge
about “shapes.” Thus the layperson
thinks that “shapes” was the concept being tested in the first place, and does
anyone really need to remember that a midsegment of a triangle is half the
length of the side to which it is parallel?

So now the Common Core Standards and the SAT have
essentially gutted geometry from the curriculum. Only the bits about shapes that are essential
to trigonometry and to transformations (since there is an increased emphasis on
graphing functions by transformations) have been kept. Formal definitions and
proof are no longer included. For true
mathematicians this means that real math is no longer taught in kindergarten
through 12

^{th}grade at all. What’s left is just the arithmetic and modeling needed for science and statistics. Where will our future mathematicians come from?
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