Skip to Main Content
Head First 2D Geometry
book

Head First 2D Geometry

by Stray (Lindsey Fallow), Dawn Griffiths
November 2009
Beginner content levelBeginner
368 pages
8h 55m
English
O'Reilly Media, Inc.
Content preview from Head First 2D Geometry
you are here 4 313
regular polygons
Great tub choice!
Your pick of the six-sided hot tub has stirred up
excitement among all the bands booked for the
festival—they think it’s gonna be amazing. And you
didn’t even have to do any more math to choose the
hexagon tub, since you already found that handy trend.
The carpenters
want this
internal angle.
We know we can divide the hexagon tub into six congruent
triangles. From this, can you find:
1) The total of all the angles of those “sector” triangles.
2) The angle that the carpenters need to build the wood
frame for the hot tub: the internal angle of the polygon.
Yeah—great, except that the
carpenter wants the dimensions and
angles of this fantasy six-sided tub
that you’ve picked. Please don’t tell me
that chopping it up into triangles is
going to find those as well....
Actually, it might.
It’s not a bad suggestion at all. We have plenty of triangle-
related tools in our toolbox, so when we’re faced with a
problem we can’t already solve, looking for ways to make it
about triangles is a great starting point. Let’s give it a go.
A handy
hexagon to
doodle on
314 Chapter 7
polygon internal angles formula
Angles in a triangle add up to 180º
There are six triangles so the total angles are:
6 x 180º = 1080º
The six angles in the middle add up to 360º ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Make: Geometry

Make: Geometry

Joan Horvath, Rich Cameron
Classical Geometry: Euclidean, Transformational, Inversive, and Projective

Classical Geometry: Euclidean, Transformational, Inversive, and Projective

I. E. Leonard, J. E. Lewis, A. C. F. Liu, G. W. Tokarsky

Publisher Resources

ISBN: 9780596808365Errata Page