Math Magic Teachers Hints, Geometry

HINTS FOR MATH TEACHERS

1. Proofs

Proofs are what give geometry its bad name.

Students get so confused as to what they need to do, they too often just give up.

I have found I could avoid that situation with one simple question:

"What do you know?"

2. Display the figure.

I copy the figure onto the overhead without any data.

No given, no numbers, just the figure itself.

Then I ask the student to look at the figure and tell me everything he can about it.

GEOMETRY, WHAT DO YOU KNOW?

3. Say it's a right triangle.

He might tell me that the sum of the angles in any triangle is equal to 180 degrees.

Since this one appears to be a right triangle, one of the angles is equal to 90 degrees.

He might include that the larger of the other angles will be across from the longest leg.

If both legs are the same, the two angles are equal to 45 degrees each.

He may then add that the length of the hypotenuse can be found by using the formula: a2 + b2 = c2

By the time he has finished his list of what he knows and we look at the given and what is to be proved, he is confident that he can handle it.

The rest of the proof is just a matter of writing down what he said to begin with.