Pop-Up Geometry:

The Mathematics behind Pop-Up Cards

by Joseph O'Rourke

Errata

Last Update:

I would like to thank Ryuhei Uehara at JAIST, who found several errors as he translated the book to Japanese.

Substantive Errors

Chap
Page
Location
Old
New
Explanation
Corrector
Date
1
10
Exercise 1.5
 The equal-length cuts are slanted, while the valley creases are vertical. (Otherwise several creases are needed to flatten.)
Ryuhei Uehara
15Sep2024
8
108
Answer to Exercise 1.5
a mountain fold halfway between the slanted valley folds, and with the same slant.
 a vertical mountain fold halfwaybetween the vertical valley folds.
Corrected answer to exercise.
Ryuhei Uehara
15Sep2024

Minor Errors: Typos, etc.

Chap
Page
Location
Old
New
Explanation
Corrector
Date
5
66
Figure 5.9 caption
x to p. p
x to p.
Typo
Ryuhei Uehara
15Sep2024
5
76
(2) display

Δ abf Δ acf

Δ abf, Δ acf
Typo
Ryuhei Uehara
15Sep2024
5
77
Exercise 5.8
the intersection of a vertical plane through the center b of the sphere Sb

the intersection of the sphere Sb and a vertical plane through the center b of Sb
Typo
Ryuhei Uehara
15Sep2024
6
92
enumerated list
(1), (3), (3)
(1), (2), (3)
Typo
Ryuhei Uehara
15Sep2024
6
94
line 8 of 6.3.3
θ = 0
θ = 0 °
Typo
Ryuhei Uehara
15Sep2024
7
101
definition of intractable
"no one knows how to solve large instances"
"no one knows how to solve large instances efficiently"
Oversight
Ryuhei Uehara
15Sep2024