Schematic diagrams of (a) square annuluses (R₁ = 24.00 mm, R₂ = 36.00 mm, D₁ = 12.00 mm, D₂ = 18.00 mm, r₁ = 2.00 mm, and r₂ = 3.00 mm), (b) square and circular annuluses (θ = 9°, R₁ = 14.00 mm, R₂ = 18.00 mm, D₁ = 12.00 mm, D₂ = 18.00 mm, r₁ = 2.00 mm, and r₂ = 3.00 mm), (c) rhomboic annuluses (θ = 60°, d₁ = 7.22 mm, d₂ = 12.50 mm, D₁ = 10.83 mm, D₂ = 18.75 mm, r₁ = 2.00 mm, and r₂ = 3.00 mm), and (d) triangular annuluses (R₁ = 26.27 mm, R₂ = 39.40 mm, r₁ = 2.00 mm, r₂ = 3.00 mm, and θ = 60°). Pressure–field amplitude patterns for ((e)–(g)) square annuluses, ((h)–(j)) square and circular annuluses, ((k)–(m)) rhomboic annuluses, and ((n)–(p)) triangular annuluses with different incident positions.