Math 360: Introduction to Modern Geometry
Spring 2026
Instructor: Prof. Cleary
E-mail: scleary (at sign) ccny.cuny.edu
Office: Marshak 301C
Phone: 650-5122
Office Hours: see webpage here for up-to-date office hours.
Text: Stahl, The Poincare Half-Plane, Jones and Bartlett Publishing. Second edition!
Course documents:
Announcements:
- Sorry, there was a spurious quiz from another course on Brightspace for a bit- that has been removed.
- Exams graded, scores on Brightspace.
- Bonus office hours 8am-8:45am Thursday Mar 5 to help prepare for Exam 1.
- To help understand symmetry of figures, the Kali, KaleidoTile, and Kaleido Paint programs are available free at geometrygames.org
- Exam 1 coming up, Thurs Mar 5th. Here are some sample exam questions to help prepare.
- Tuesday, Feb 24: notes from class on Brightspace under "Content".
- Tuesday, Feb 24: remote learning day, look for a Zoom link on Brightspace.
- Tuesday, Feb 17: no classes, our 360 class does not meet
- Monday, Feb 16: campus closed, no classes, does not affect our 360.
- Thursday, Feb 12: campus closed, our 360 class does not mee
- The plan is to meet in NAC 1/511E, the room to the right as you enter the Artino Lab.
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There are two straightforward quizzes on Blackboard which should be completed by Feb 3rd at 9am. (not yet, and it will be on Brightspace, sorry!)
- Students enrolled in the course should have gotten a Welcome email on Jan 21st. If you are enrolled but did not get an email, make sure your CUNY First and Brightspace emails are set up properly.
- First class meets Jan 27th.
- E. Abbott Abbott's Flatland is available online in many places, for example here or at Project Gutenberg.
- Euclid's Elements are available online in many places, for example here.
- Hilbert's Axioms are available online in many places, for example here.
- Note that there are different editions of Stahl's book. You want the second edition, which has a greenish cover with yellow and has ISBN 978-0763753818, not the one with the blue cover which has an ISBN which ends in 202984.
- There is a webpage with errata for the book here
- The Stahl book is unfortunately on the expensive side- there is a copy of the text on library reserve. The first edition is available for much less expense but there are a few changes, including how exercises are grouped and the exercises themselves have been changed somewhat.
There are used copies available at ABE and elsewhere.
Homework Assignments
Other Links