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docs/lib3x-tri_circumcenter.md

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+# tri_circumcenter
+
+The `tri_circumcenter` function returns the circumcenter of a 2D triangle. 
+
+**Since:** 3.1
+
+## Parameters
+
+- `shape_pts` : the vertices of a 2D triangle.
+
+## Examples
+
+    use <triangle/tri_circumcenter.scad>;
+   
+    assert(tri_circumcenter([[0, 0], [10, 20], [15, 10]]) == [3.75, 10.625]);

docs/lib3x-tri_incenter.md

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+# tri_incenter
+
+The `tri_incenter` function returns the incenter of a 2D triangle. 
+
+**Since:** 3.1
+
+## Parameters
+
+- `shape_pts` : the vertices of a 2D triangle.
+
+## Examples
+
+    use <triangle/tri_incenter.scad>;
+   
+    assert(tri_incenter([[0, 0], [15, 0], [0, 20]]) ==  [5, 5]);