We found ourselves out at the creek again looking for rocks. (We have a habit of doing this. My pockets are always crammed full of rocks by the time we get back in the house…)
What did we find? Let’s take a look:
We found POLYGONS (i.e., flat shapes with three or more straight sides)!!
- a square: A 4-sided shape where all sides have equal length and every angle is a right angle**
- two triangles: 3-sided shape with three sides
- a right triangle: a triangle that has a right (90°) angle
- a trapezoid: 4-sided shape (also known as a quadrilateral) with one pair of opposite sides parallel
- a parallelogram: 4-sided shape with opposite sides parallel and equal in length and opposite angles equal
- an irregular pentagon: a 5-sided shape that does not have sides/angles equal in length/measure.
**Okay, if we measured accurately, our square would not be a square, it would be a rectangle, or it could possibly be an irregular decagon if we really get close with our measuring of angles and sides, but it’s close enough for today’s spontaneous math lesson. The same applies for all of the above. Actually, if you really want to be specific, these are not 2-D figures. They’re rocks, after all. But if you put perfectionism aside for a moment, it’s fun turning a rock collection into a math lesson! (I’m just plain giddy over it.)
If you’re not as “into” geometry as I am, you can think of it as David does: “That’s a pizza rock, not a vegetable rock…” (referring to the triangular-shaped rocks).
We’ll work on a more formal classification of rocks at a later date. Right now, the classification consists of: “shape” rocks, “state” rocks, and “letter” rocks.
And so this is what you get when you have a mom who was a former math teacher that LOVES geometry who was also a former petroleum engineer that LOVES geology…