-1/2<=x - x_0<=1/2 and -1/2<=y - y_0<=1/2 (assuming center (x_0, y_0))

vertex count | 4 edge count | 4

diagonal length | sqrt(2)≈1.41421 area | 1 perimeter | 4 central angle | 90° = π/2 rad≈1.571 rad interior angle | 90° = π/2 rad≈1.571 rad interior angle sum | 360° = 2 π rad≈6.283 rad apothem | 1/2 = 0.5 (assuming center (x_0, y_0))

{4}

square graph

square