Head First 2D Geometry

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regular polygons

Work the formula for circle area backward to get the butt count

for the circle shaped hot tub.

Is 19.6 butts a lot or a little?

One number on its own isn’t enough to choose a hot tub—

you want the MOST possible butt-space for your 6 square

meters of area. You need to tackle the other hot tubs shapes

to find out if they’re better or worse than the square tub.

Q:

Half a meter per butt? Really?

A: OK, so we all know that butt-size is one of life’s interesting

variables. Obviously not all butts are the same size, but in this

problem that’s not too important. Even if you had a bunch of people

with more generously proportioned butts, you’d still fit more into the

biggest perimeter, so it’s still a useful comparison.

Q:

19 butts or 19.6 butts? I’ve never met anyone with 0.6 of

a butt.

A: That’s true, you’d really round down to 19. Only whole butts

can get in the tub (unless you count a really skinny one as a 0.6).

That 0.6 gives a little extra room to the 19 folk in there though, so it’s

worth keeping those decimals in case we end up choosing between

two tubs which both have butt counts between 19 and 20.

Reviewing isn’t cheating! Circle

area formulas: page 234.

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