L20_A
1.Review: The Geometric Meaning of the Second Fundamental Form
2. Proposition: Meusnier
3. Example: Unit Sphere
L20_B
1. Definition: Normal Section
2. Derivation: Define the Normal Curvature by Normal Section
L20_C
1. Definition: Principal Curvatures and Principal Directions
2. Definition: Line of Curvature
3. Proposition: Olinde Rodrigues
4. Derivation: Euler Formula
10610 池盷恩同學幾何筆記.pdf
