Around the edge I roam;
I look into the middle,
Where the area has its home.
We measure perimeter by adding sides:
How long is every one?
That tells you how much fence you’d need,
Or far you’d have to run.
We measure area with squares:
How many can we glue?
Just multiply the base times height
And area is through.
You then divide by 2.)
For complicated shapes,
Cut into smaller shapes you know,
If lengths aren’t labeled,
Look across at opposite lengths that show.
We measure volume space with cubes:
How much space will there be?
From any corner, look three ways
And multiply what you see.
(That’s base times height times depth
to give dimensionality.)
To see how triangles really behave when they’re letting all their points hang out, check out the polygon partiers in this video:
Outside of every circle,
Let’s build a circle fence;
And give that circle fence a name:
It’s called “Circumference”.
Let’s stretch a cord across that fence,
Straight to the other side;
“Diameter” is the fancy name;
Our circle it divides.
With two of our diameter cords,
We try to wrap around,
But two won’t reach;
With D times 3 circumference is found.
(Of course, the opposite is true:
Divide circumference by 3 to find diameter, too.)
A more exact result you’ll see,
If you use pi (Π) instead of 3.
(That’s 3-point-1-4 and some more,
But it’s close enough with 3-1-4.)
They’ll try to trick you:
They’ll give radius instead of D;
But r times 2 makes D,
And D times 3 will give you C.
(Or 3-point-1-4, pi, to get
A more exact circumference yet.)
But if you can’t remember “r”
or “radius”, think “ray”:
Two rays of sun join up as one;
And start a brand-new Day.
I’d be remiss to end without including two Pi items well-known in nerd circles (she said, sneeringly, while secretly enjoying the videos as well):
edited 11/13 to shrink some images for phones, to note that ya’ need to click “Redisplay” to reanimate some .gifs by the time you get to ’em, to add a coupla’ more nice .gifs while I was in here, and, last, to toss off another verse which ain’t so hot, but I felt like it anyhow…and lastly last, to add a tau reference (but I draw the [arc?] at eta!).