# New in *MathWorld* -- February
2019

### Wednesday February 13, 2019

- Regular Hexagon (modified)
- Regular Octagon (modified)
- Regular Pentagon (modified)

### Monday February 11, 2019

- Line Segment Picking (modified)

### Sunday February 10, 2019

- Li's Criterion (modified)
- Xi-Function (modified)

### Friday February 8, 2019

- Ball Line Picking (modified)
- Line Picking (modified)
- Li's Criterion (modified)
- Mean Line Segment Length
- Mean Tetrahedron Volume
- Mean Triangle Area
- Robbins Constant (modified)
- Tetrahedron Picking
- Triangle Picking

### Thursday February 7, 2019

- RiemannXi (modified)
- Xi-Function (modified)

### Tuesday February 5, 2019

- Discorectangle (modified)
- Obround (modified)
- Sausage Body (modified)
- Stadium (modified)

### Monday February 4, 2019

- Acute Golden Rhombohedron (modified)
- Obtuse Golden Rhombohedron (modified)

### Sunday February 3, 2019

- Acute Golden Rhombohedron (modified)
- Antibipyramid
- Antidipyramid
- Obtuse Golden Rhombohedron (modified)
- Trapezohedron (modified)
- Trigonal Deltohedron
- Trigonal Trapezohedron (modified)

### Saturday February 2, 2019

- Acute Golden Rhombohedron (modified)
- Obtuse Golden Rhombohedron (modified)

### Friday February 1, 2019

- Bilinski Dodecahedron (modified)
- Hexagon (modified)
- Regular Hexagon (modified)
- Rhombic Icosahedron (modified)

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