y=a:ρsinθ=a,θ∈[π/4,π/2];
y=3a:ρsinθ=3a,θ∈[π/4,arctan(3/2)];
y=x:θ=π/4,ρ∈[√2a,3√2a];
y=x+a:ρcos(θ+π/4)+(√2/2)a=0,θ∈[arctan(3/2),π/2];
y=a:ρsinθ=a,θ∈[π/4,π/2];
y=3a:ρsinθ=3a,θ∈[π/4,arctan(3/2)];
y=x:θ=π/4,ρ∈[√2a,3√2a];
y=x+a:ρcos(θ+π/4)+(√2/2)a=0,θ∈[arctan(3/2),π/2];