Errata for
Henderson/Taimina, *Experiencing Geometry* (3^{rd} edition)

Changes in Red.

pg xix, line 8-10:
“and we will post patterns for making paper models and sources for crocheted hyperbolic surfaces on the Experiencing Geometry Web page as they become available.”

replace with

“and you can find patterns of making paper models on the Experiencing Geometry Web page; also see Daina Taimina, *Crocheting Adventures with Hyperbolic Planes* (AK Peters, 2009).”

pg xix, line 23: “on how to use this book in a course) by sending a request via e-mail to George_Lobell@prenhall.com or calling 1-201-236-7407.”

should be changed to

“on how to use this book in a course) by calling Faculty Services at 1-800-526-0485.”

pg 13, line 12-:

out using its center. When the
lengths *g* and *f* are equal, then *Q
*draws the

pg 63, line 15:

Change “I” to “We”

pg 67, line 9 of Problem **5.2**:

replace "(*w*,0)" with "(*w*,*s*)"

pg 106, equation in Part **c**-:

replace "(*n - *1)" with "(*n *- 2)"

pg 114, line 11:

*any transversal
passing through the midpoint of the segment of l*

* *

pg 115, line 18:

2. *Parallel lines are lines such that every
transversal cuts them at*

* *

pg 134, Figure 10.6:
Remove the three *d*’s along the bottom of the figure (leave the
three *d*’s near the top.

pg 147, line 2-: this one is not important

some students have affectionately called them “horrorcycles.”] Note that

pg 181, line 4-:

which we will prove in Problem **15.1a**, but the special case we need is

pg 196, line 2:

use that result to show that *ac*
= *bd* or, in equivalent form, *a/d *= *b/c*.

pg 198, line 8:

need properties of similar
triangles that are investigated in Problem **13.4**.

pg 259, Figure 18.15:

Switch the direction of both sides of the octagon that are marked with four arrows.

pg 271, line2 (just below Figure 19.3):

This leads to *x*
= *b/*2 − .
Note that if *c* > (*b*/2)^{2}, this geometric

pg 387: Remove “~~59~~, ” from the
“Gauss” entry, which should now read:

Gauss, 103, 140, 142, 226, 347

pg 390: Poincaré, 258, 354

Conjecture, 257-8

disk model. 212, 234, 242-3

projective disk model, **234**, 244

Errata for
Henderson/Taimina, *Experiencing Geometry* (3^{rd} edition)

Instructor’s Manual

Changes in Red.

pg 13, Figure 7: The points *C*, *P*, and *D *should be labeled as follows:

The piont "*C*" is where the two links of length *s* intersect.

The point "*P*" is where the link of length *f* intersects two links of length *d*.

The point "*D*" is the other end of the link of length *f*.

pg 93, equation in Part **c**-:

replace "(*n - *1)" with "(*n *- 2)"

pg 106, line 3:

* they are
also parallel transports along any transversal
passing through the midpoint of the*

* *

pg 108, line 13:

2. *Parallel lines are lines such that every transversal cuts them at congruent angles*:
or

* *

pg 138, at the end of the first paragraph add:

Draw in the two diagonals and first use SAS and then SSS.

pg 147, Figure 10.6:
Remove the three *d*’s along the bottom of the figure (leave the
three *d*’s near the top.

pg 159, line 2: this one is not important

called them “horrorcycles.”] Note that *on the plane
circles of infinite radius are straight lines.*

pg 201, line 8:

that we will
prove in Problem **15.1a**, but the special
case we need is easy to see now. In particular

pg 213, last five lines:

Now,
if θ = π/2, then the above equal areas are the products *ac *= *bd*, and
cross-dividing we

get the desired *a/d = b/c*. Then we can define the usual trigonometric
functions for right

triangles. For arbitrary θ the above
equal areas are *ac *sinθ = *bd *sinθ, so again cross-dividing, we

get:

*a/d=b/c.*

pg 215, line 5-:

triangles that are investigated
in Problem **13.4**.

pg 275, Figure 18.15: Switch the direction of both sides of the octagon that are marked with four arrows.

pg 287, line 1 (just below Figure 19.3):

This leads to *x* = *b/*2 − .
Note that if *c* > (*b*/2)^{2}, then this geometric
solution is impossi-