grooved rectangular plate 3d model

Create a 3D printable rectangular plate with the following specifications: - Plate size: 50 mm length, 40 mm width, 2 mm thickness - On top surface: repeated triangular grooves (V-shape pattern) - Each groove: - width: 1 mm - height: 0.5 mm - angle: 90 degrees - Number of grooves: 40 - Spacing (pitch): 1 mm between grooves - Grooves aligned in parallel along the length The model must be clean, watertight, and suitable for 3D printing (STL format). No textures, only geometry.