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Introduction to Geometry

Fundamentals of geometry, including angles, triangle similarity and congruence, complicated area problems, mastering the triangle, special quadrilaterals, polygons, the art of angle chasing, power of a point, 3-dimensional geometry, transformations, analytic geometry, basic trigonometry, geometric proof, and more.

24 weeks

Diagnostics

ARE YOU READY? DO YOU NEED THIS?

Documents

SYLLABUS
24 weeks ARE YOU READY? DO YOU NEED THIS? SYLLABUS  

Schedule

Thursday
Aug 29 - Mar 6
7:30 - 9:00
PM ET
Aug 29 - Mar 6
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
CLOSED
Friday
Sep 6 - Mar 7
7:30 - 9:00
PM ET
Sep 6 - Mar 7
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Tuesday
Sep 10 - Mar 11
7:30 - 9:00
PM ET
Sep 10 - Mar 11
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL

STARTING SOON

Sunday
Sep 29 - Mar 30
1:00 - 2:30
PM ET  
Sep 29 - Mar 30
1:00 - 2:30 PM Eastern
12:00 - 1:30 PM Central
11:00 - 12:30 PM Mountain
10:00 - 11:30 AM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Sunday
Oct 27 - Apr 27
7:30 - 9:00
PM ET
Oct 27 - Apr 27
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Monday
Nov 11 - May 12
7:30 - 9:00
PM ET
Nov 11 - May 12
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Wednesday
Nov 13 - May 14
9:30 - 11:00
PM ET  
Nov 13 - May 14
9:30 - 11:00 PM Eastern
8:30 - 10:00 PM Central
7:30 - 9:00 PM Mountain
6:30 - 8:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Tuesday
Dec 10 - Jun 3
7:30 - 9:00
PM ET
Dec 10 - Jun 3
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Wednesday
Jan 8 - Jun 18
7:30 - 9:00
PM ET
Jan 8 - Jun 18
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Thursday
Jan 30 - Jul 10
7:30 - 9:00
PM ET
Jan 30 - Jul 10
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Friday
Feb 14 - Aug 1
7:30 - 9:00
PM ET
Feb 14 - Aug 1
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Tuesday
Mar 4 - Aug 12
7:30 - 9:00
PM ET
Mar 4 - Aug 12
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Sunday
Mar 23 - Sep 21
7:30 - 9:00
PM ET
Mar 23 - Sep 21
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL
Wednesday
Apr 23 - Oct 1
7:30 - 9:00
PM ET
Apr 23 - Oct 1
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$690 (~$29/lesson)
$755 w/books
$690 (~$29/lesson)
With Books $755
ENROLL

AoPS Holidays

There are no classes October 31, November 25 ‐ December 1, December 21 ‐ January 3, May 24 ‐ 26, July 4 ‐ 6, and August 29 ‐ September 1, 2025.

Who Should Take?

This is the most challenging of our Introduction series of classes. We recommend that students complete our Introduction to Algebra B course, or are able to pass the Introduction to Algebra B post-test, prior to taking Introduction to Geometry.

Lessons

1 Angles
2 Triangle Angles and Congruent Triangles
3 Isosceles & Equilateral Triangles, Perimeter, and Area
4 Similar Triangles
5 Similar Triangles and Right Triangles
6 More Right Triangles!
7 Special Parts of a Triangle
8 Special Parts of a Triangle, Continued!
9 Quadrilaterals
10 More Quadrilaterals
11 Polygons
12 Geometric Inequalities
13 Introduction to Circles
14 Circles and Angles
15 Tangents
16 Power of a Point
17 3D Geometry Part 1
18 3D Geometry Part 2
19 Transformations
20 Analytic Geometry
21 More Analytic Geometry
22 Basic Trigonometry
23 Problems!
24 More Problems!

Required Textbook

Introduction to Geometry
By Richard Rusczyk
A full course in challenging geometry for students in grades 7-10, including topics such as similar triangles, congruent triangles, quadrilaterals, polygons, circles, funky areas, power of a point, three-dimensional geometry, transformations, introductory trigonometry, and more.
Related course: Introduction to Geometry

This has probably been the best AoPS class I've had. It was the most challenging, but the instructor was a great teacher. He gave good explanations and I was able to understand the concepts, which has been a challenge for me with geometry. Overall, it was a great class.