Abstract. If X is a geodesic metric space and 𝑥₁, 𝑥₂, 𝑥₃ ∈ 𝑋, a geodesic triangle 𝑇 = {𝑥₁, 𝑥₂, 𝑥₃} is the union of the three geodesics [𝑥₁𝑥₂], [𝑥₂𝑥₃] and [𝑥₃𝑥₁] in 𝑋. The space 𝑋 is ...