The Wolfenstein parameter λ of the CKM matrix has the observed value λ = 0.2245 ± 0.0008. The Standard Model does not explain why. The canvas model provides two independent derivations: λ = 1/5 = 0.2 from gauge subspace dimensions, and α = (π−2)/(π+2) ≈ 0.222 from the geometry of perpendicular wave intersection. The observed value sits between them, closer to α. This paper shows that both values have a common geometric origin. They are tangents of angles that represent corrections to π/4—the angle that bisects the first quadrant of the unit circle, where the four dynamic primitives (Order, Amplitude, Acceleration, Polarity) are organized. What this paper provides: · A geometric interpretation of the two candidate values. Both 1/5 and α are expressed as tangents of specific angles: · λ = 1/5 = tan(arctan(1/5)). The angle arctan(1/5) ≈ 11.31° appears in Machin's formula for π/4, connecting to the pentagonal structure of the gauge subspaces (SU(2) dimension 2 + SU(3) dimension 3 = 5). · α = (π−2)/(π+2) = tan(π/4 − arctan(2/π)). The correction arctan(2/π) is determined by the circle's own geometry—the ratio of the diameter (2) to the semicircle (π).· An explanation of why two values arise. The gauge structure is rational: integers {1,2,3} from the charge primitive determine the gauge group and base mixing parameters (1/5). The spacetime geometry is transcendental: the angle π/2 determines orthogonality of spatial axes, waveform asymmetry, and the modulation of effective couplings (α). The physical CKM parameter reflects both structures.· A demonstration that both angles are measured from π/4 as a reference. θ_λ = arctan(1/5) ≈ 0.1974 rad; θ_α = π/4 − arctan(2/π) ≈ 0.2185 rad. Both are corrections to π/4 = 0.7854 rad. The difference between them (≈ 0.021 rad, ≈ 1.2°) is the irreducible gap between rational and transcendental descriptions of the same physical quantity.· A physical interpretation of the observed value. λ = 0.2245 corresponds to θ_obs = arctan(0.2245) ≈ 0.2214 rad ≈ 12.69°. This is closer to θ_α (12.52°) than to θ_λ (11.31°), indicating that geometric modulation dominates over the rational scaffold. The residual difference (≈ 0.17°) may reflect incomplete attractor dynamics.· A connection to the π/2 waveform asymmetry. The same geometric primitives (Chirality P5, Angle P7) that produce the π/2 waveform asymmetry also modulate the effective CKM mixing. If the π/2 asymmetry is confirmed experimentally, it validates the geometric modulation that shifts λ toward α. Why this matters: The CKM parameter is not an unexplained constant. It is a window into the interplay between gauge structure (rational, integer-based) and spacetime geometry (transcendental, π-based). The gap between 1/5 and α is not an error to be eliminated—it is the irreducible difference between rational and transcendental descriptions of the same physical quantity. The observed λ sits between them, closer to α, because the geometry of perpendicular wave intersection dominates over the rational gauge scaffold. Keywords: CKM matrix, Wolfenstein parameter λ, canvas model, gauge subspaces, π/2 waveform asymmetry, arctan representation, π/4, rational vs transcendental, CKM geometry, quark mixing