High school geometry
Learn high school geometry—transformations, congruence, similarity, trigonometry, analytic geometry, and more (aligned with Common Core standards).
9 units196 videos19 hours
Learn it live with a class on Puzzicle · Teachers: use it with your class
Unit 1: Performing transformations
Intro to Euclidean geometry
Introduction to rigid transformations
Translations
Rotations
Reflections
Unit 2: Transformation properties and proofs
Rigid transformations overview
Dilation preserved properties
Properties & definitions of transformations
Symmetry
Proofs with transformations
Unit 3: Congruence
Transformations & congruence
Triangle congruence from transformations
Proving the SSS triangle congruence criterion using transformations ✓ Check-ins5:47
Proving the SAS triangle congruence criterion using transformations ✓ Check-ins4:31
Proving the ASA and AAS triangle congruence criteria using transformations ✓ Check-ins7:24
Why SSA isn't a congruence postulate/criterion ✓ Check-ins7:24
Congruent triangles
Theorems concerning triangle properties
Working with triangles
Theorems concerning quadrilateral properties
Proof: Opposite sides of a parallelogram ✓ Check-ins8:30
Proof: Diagonals of a parallelogram ✓ Check-ins9:06
Proof: Opposite angles of a parallelogram ✓ Check-ins4:08
Proof: The diagonals of a kite are perpendicular ✓ Check-ins11:06
Proof: Rhombus diagonals are perpendicular bisectors ✓ Check-ins4:04
Proof: Rhombus area ✓ Check-ins5:07
Proofs of general theorems
Constructing lines & angles
Geometric constructions: congruent angles ✓ Check-ins4:09
Geometric constructions: parallel line ✓ Check-ins2:03
Geometric constructions: perpendicular bisector ✓ Check-ins1:26
Geometric constructions: perpendicular line through a point on the line ✓ Check-ins1:12
Geometric constructions: perpendicular line through a point not on the line ✓ Check-ins2:42
Geometric constructions: angle bisector ✓ Check-ins2:17
Unit 4: Similarity
Definitions of similarity
Introduction to triangle similarity
Solving similar triangles
Angle bisector theorem
Solving problems with similar & congruent triangles
Proving relationships using similarity
Pythagorean theorem proof using similarity ✓ Check-ins9:52
Exploring medial triangles ✓ Check-ins11:33
Proof: Parallel lines divide triangle sides proportionally ✓ Check-ins6:32
Proving slope is constant using similarity ✓ Check-ins7:56
Proof: parallel lines have the same slope ✓ Check-ins5:49
Proof: perpendicular lines have opposite reciprocal slopes ✓ Check-ins8:55
Solving modeling problems with similar & congruent triangles
Unit 5: Right triangles & trigonometry
Pythagorean theorem
Pythagorean theorem proofs
Special right triangles
Ratios in right triangles
Introduction to the trigonometric ratios
Solving for a side in a right triangle using the trigonometric ratios
Sine & cosine of complementary angles
Modeling with right triangles
Unit 6: Analytic geometry
Distance and midpoints
Dividing line segments
Problem solving with distance on the coordinate plane
Parallel & perpendicular lines on the coordinate plane
Equations of parallel & perpendicular lines
Parallel lines from equation ✓ Check-ins3:48
Parallel lines from equation (example 2) ✓ Check-ins3:03
Parallel lines from equation (example 3) ✓ Check-ins2:42
Perpendicular lines from equation ✓ Check-ins3:29
Writing equations of perpendicular lines ✓ Check-ins3:01
Writing equations of perpendicular lines (example 2) ✓ Check-ins1:45- Proof: parallel lines have the same slope ✓ Check-ins5:49
- Proof: perpendicular lines have opposite reciprocal slopes ✓ Check-ins8:55
Unit 7: Conic sections
Graphs of circles intro
Standard equation of a circle
Expanded equation of a circle
Focus and directrix of a parabola
Unit 8: Circles
Circle basics
Arc measure
Arc length (from degrees)
Introduction to radians
Arc length (from radians)
Inscribed shapes problem solving
Proofs with inscribed shapes
Properties of tangents
Proof: Radius is perpendicular to tangent line ✓ Check-ins8:41
Proof: Segments tangent to circle from outside point are congruent ✓ Check-ins3:56
Tangents of circles problem (example 1) ✓ Check-ins4:37
Tangents of circles problem (example 2) ✓ Check-ins3:47
Tangents of circles problem (example 3) ✓ Check-ins2:34
Constructing regular polygons inscribed in circles
Constructing circumcircles & incircles
Constructing a line tangent to a circle
Unit 9: Solid geometry
2D vs. 3D objects
Cavalieri's principle and dissection methods
Volume and surface area
Learn this with a class
With a class on Puzzicle this course runs as a timetable of live study parties: your batch watches together and answers the check-ins, sometimes with a teacher leading.
Course content © Khan Academy, used under CC BY-NC-SA. See this course on Khan Academy.