δ-slim triangle
γ₀
⊂
B
δ
(
γ₁ ∪ γ₂
)
side
γ₀
γ₁
γ₂
δ
0.70
fit
B
δ
(γ
j
∪ γ
k
)
witness
(λ,0)-quasi-geodesics
background geodesics
needed δ
—
witness
—
λ bound
—