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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

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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
FULL
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
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
$710 (~$30/lesson)
$775 w/books
$710 (~$30/lesson)
With Books $775
ENROLL

AoPS Holidays

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

I really enjoyed taking my first AoPS class. I always thought that online classes weren't very good. I was mistaken after I took this class. Not only did Introduction to Geometry help me become a better math student, it also helped me to think more abstractly and look for multiple roads to solve a problem. I enjoy the way the classroom is run and the pace was very nice. The class wasn’t boring at all. This class challenged me to become a better thinker and was way more challenging than regular school courses. I am also very glad that AoPS also included a little bit of a social aspect to math with the message boards. I made a lot of friends through this course. In school, I am always made fun of for being ahead of all of the other students. On AoPS I actually feel accepted for once because I can interact with kids that are more advanced than I am and also I learn from them. I will definitely take another AoPS class.