L8_A
1. Two Subclasses of Developable surface
L8_B
1. Two Subclasses of Developable surface (cont.)
2. Example: The Envelope of the Family of Tangent Planes
Along a Curve of a Surface
Along a Curve of a Surface
L8_C
1. The Envelope of the Family of Tangent Planes Along a
Curve of a Surface Is Developable
Curve of a Surface Is Developable