Outline
CCSS High School: Geometry (Challenges)
This GeoGebra book contains links to a plethora of problems teachers can use to provide challenging enrichment activities for students that excel within the regular curriculum. Many of the problems in this book come from those posted on Twitter by Antonio Gutierrez (https://twitter.com/gogeometry) and Alexander Bogomolny (https://twitter.com/CutTheKnotMath).
Each challenge (and corresponding animation) is mapped to one (or more) of the CCSS High School: Geometry standards.
Table of Contents
HSG.CO.C.9
HSG.CO.C.10
- Medians & Equal Areas!
- Animation 74
- Animation 90
- Euler Line (Informal Investigation)
- Euler Line Generator
- Morley Action!
- Animation 113
- Napoleon Motion!
- Animation 14
- Hexagonal Napoleon Theorem?
- Animation 172
- Vivani Action!
- Equilateral Action (1)!
- Animation 91
- Equilateral Action (2)!
- Animation 94
- Equilateral Action (3)!
- Animation 107
- Equilateral Action (4)!
- Animation 108
- Equilateral Triangle and Rectangle (Area Problem)
- Animation 154
- Equal Triangular Areas in a Regular Pentagon
- Animation 194
- NCTM Calendar Problem (11-2-2016)
- Animation 139
- 9 Point Circle Action
- Animation 34
- 9-Point Circle Action (Part 2)
- Animation 106
- 9-Point Circle Action (Part 3A)
- 9-Point Circle (Informal Investigation)
- Animation 71
- 9-Point Circle Action (Part 3B)
- 9-Point Circle Action (Part 4)
- Animation 53
- 9-Point Circle Action (Part 5)
- Animation 115
- Isosceles Triangle: Surprising Theorem!
- Animation 121
- Cut-The-Knot Action !!!
- More Triangle Action!!!
- Animation 163
- Triangle Median & Circles Action!!!
- Animation 164
- Desargues Action!!!
- Animation 209
- GoGeometry Action 10!
- Animation 219
- GoGeometry Action 14!
- Animation 223
- GoGeometry Action 17!
- Animation 228
- GoGeometry Action 18!
- Animation 229
- Cut-The-Knot-Action 8!
- Animation 230
- GoGeometry Action 20!
- Animation 233
- Cut-The-Knot Action 9!
- Animation 234
- Carnot Action! = GoGeometry Action 27!
- Animation 241
- GoGeometry Action 29!
- Animation 244
- GoGeometry Action 30!
- Animation 245
- Incircle + Excircle = GoGeometry Action 31!
- Animation 246
- GoGeometry Action 32!
- Animation 247
- Cut-The-Knot Action 10!
- Animation 248
- GoGeometry Action 34!
- Animation 250
- Cut-The-Knot-Action 12!
- Animation 251
- GoGeometry Action 35!
- Animation 252
- GoGeometry Action 37!
- Animation 254
- GoGeometry Action 38!
- Animation 255
HSG.CO.C.11
- Finsler-Hadwiger Action!!!
- Animation 110
- Thebault Action!!!
- Animation 83
- Van Aubel Action!!!
- Animation 109
- Square Problem
- 3 Squares Problem
- Animation 120
- Harmonic Mean In an Isosceles Trapezoid
- Square Action! (Proof Problem 1)
- Cut-The-Knot Action (4)!
- Animation 213
- Rhombus Action + Sequel = GoGeometry Action 7!
- Animation 215
- GoGeometry Action 11!
- Animation 220
- GoGeometry Action 12!
- Animation 221
- GoGeometry Action 18!
- Animation 231
- GoGeometry Action 21!
- Animation 235
- GoGeometry Action 22!
- Animation 236
- GoGeometry Action 23!
- Animation 237
- GoGeometry Action 24!
- Animation 238
- GoGeometry Action 36!
- Animation 253
HSG.CO.D.12
HSG.C.A.2
- Butterfly Theorem Action!
- Animation 132
- Not Your Everyday Chord & Tangent Theorem
- Animation 133
- Cut-The-Knot Action (2) !!!
- Animation 152
- Int+Ext Tangent Action!
- Animation 155
- Square, Tangent, and Two Congruent & Tangent Circles
- Animation 153
- GoGeometry Action 1!
- Animation 205
- GoGeometry Action 2!
- Animation 206
- GoGeometry Action 3!
- Animation 207
- GoGeometry Action 4!
- Animation 208
- GoGeometry Action 5!
- Animation 210
- GoGeometry Action 6!
- Animation 212
- GoGeometry Action 8!
- Animation 216
- Cut-The-Knot Action (6)!
- Animation 217
- GoGeometry Action 9!
- Animation 218
- GoGeometry Action 13!
- Animation 222
- GoGeometry Action 15!
- Animation 224
- GoGeometry Action 16!
- Animation 226
- Cut-The-Knot Action 7!
- Animation 227
- GoGeometry Action 19!
- Animation 232
- Thales Action + Sequel = GoGeometry Action 25!
- Animation 239
- GoGeometry Action 26!
- Animation 240
- Carnot Action! = GoGeometry Action 27!
- Animation 241
- Incircle + Excircle = GoGeometry Action 31!
- Animation 246
- Cut-The-Knot Action 10!
- Animation 248
- Cut-The-Knot-Action 11!
- Animation 249
Links to Other CCSS High School: Geometry Standards