diff --git a/src/matrixmania/compute.py b/src/matrixmania/compute.py
index b2a15fa..360b79c 100644
--- a/src/matrixmania/compute.py
+++ b/src/matrixmania/compute.py
@@ -143,6 +143,31 @@ def rot_3D(angle: float, axis: str) -> list[list[float]]:
         ]
     raise ValueError("Axis must be one of 'x', 'y', or 'z'.")
 
+def project_ortho(point: tuple[float, float, float], scale: float = 1.0) -> tuple[float, float]:
+    """Orthogonal projection of a 3‑D point onto the xy‑plane.
+
+    Parameters
+    ----------
+    point : tuple[float, float, float]
+        Cartesian coordinates (x, y, z).
+    scale : float, optional
+        Scaling factor applied to x and y after projection. Defaults to 1.
+
+    Returns
+    -------
+    tuple[float, float]
+        Projected 2‑D coordinates (x_scaled, y_scaled).
+
+    Examples
+    --------
+    >>> project_ortho((1, 2, 3))
+    (1, 2)
+    """
+    if len(point) != 3:
+        raise ValueError("Point must be a 3‑tuple.")
+    return (point[0] * scale, point[1] * scale)
+
+
 
 if __name__ == "__main__":
 
diff --git a/test/test_matrixmania/test_projection.py b/test/test_matrixmania/test_projection.py
new file mode 100644
index 0000000..1f9f534
--- /dev/null
+++ b/test/test_matrixmania/test_projection.py
@@ -0,0 +1,15 @@
+import pytest
+
+from matrixmania.compute import project_ortho
+
+
+def test_project_ortho_default():
+    """Projektionsfunktion ohne Skalierung"""
+    point = (1.0, 2.0, 3.0)
+    assert project_ortho(point) == (1.0, 2.0)
+
+
+def test_project_ortho_scaled():
+    """Projektionsfunktion mit Skalierung"""
+    point = (1.0, 2.0, 3.0)
+    assert project_ortho(point, scale=100) == (100.0, 200.0)