380 17 “Sphere to cone”: polar aspect
Θ = Φ 0
Φ 0
Φ 1 < Θ < Φ 2
Φ 1
Φ 2
“tangent cone”
“secant cone”
Fig. 17.2. Tangent cone and secant cone.
slant height r 0
circle-of-contact Φ = Φ 0
central meridian Λ = Λ 0
meridian Λ = Λ P
Θ
apex S
vertex angle Θ ∈ (0, π/2)
N
P
Φ 0
R
R 0
O
Fig. 17.3. Geometry of a right tangent cone.
Θ = Φ 0
Φ 0
Φ 1 < Θ < Φ 2
Φ 1
Φ 2
“tangent cone”
“secant cone”
Fig. 17.2. Tangent cone and secant cone.
slant height r 0
circle-of-contact Φ = Φ 0
central meridian Λ = Λ 0
meridian Λ = Λ P
Θ
apex S
vertex angle Θ ∈ (0, π/2)
N
P
Φ 0
R
R 0
O
Fig. 17.3. Geometry of a right tangent cone.