Geometry· Study notes
Shape and Angle
Proof-based plane geometry: angles, parallel lines, congruent and similar triangles, right-triangle trigonometry, polygons, circles, area, volume and transformations.
What you'll be able to do
- Write two-column and paragraph proofs
- Prove triangles congruent or similar and use the consequences
- Apply the circle theorems
- Compute areas and volumes of standard figures
Read the notes as a guided lesson
Walk the notes one box at a time — prose, worked examples, quick checks — with a timed practice round after every section. For the full course with interactive lessons, go back to the course.
Every test ends with a score by topic and a list of what to revisit. Test out of a topic with 80% or better to mark it mastered.
Topics
Points, Lines & Planes
8 lessonsFoundations: undefined terms, segments, midpoints & distance
Angles
9 lessonsNaming, classifying, and solving for angle measures
Parallel & Perpendicular Lines
10 lessonsEverything you need to name angles, find them, and work with slopes
Triangles & Congruence
10 lessonsClassifying, angle rules, congruence shortcuts, and a first proof
Similarity
10 lessonsRatios, similar polygons & triangles, indirect measurement, midsegments & scaling
Right Triangles & Trig
11 lessonsPythagoras, special triangles, SOH-CAH-TOA, and angles of elevation
Quadrilaterals & Polygons
10 lessonsVocabulary, angle formulas, special quadrilaterals, and the family tree
Circles
10 lessonsParts, circumference, area, angles, tangents, chords, and equations
Area & Volume
8 lessonsFlat shapes, solid shapes, and the formulas that measure them