Jackson, Frank

• Anticenter
• Congruent Incircles
• Cross Polytope
• Euler Line
• Excentral Triangle
• First Yff Circles Triangle
• Fuhrmann Circle
• GEOS Circle
• Gergonne Line
• Incenter
• Inner Soddy Circle
• Johnson Circles
• Johnson Circumconic
• Johnson's Theorem
• Johnson Triangle
• Johnson-Yff Circles
• Medial Triangle
• Nine-Point Circle
• Orthic Axis
• Orthocenter
• Orthocentroidal Circle
• Outer Soddy Circle
• Prime Sums
• Pythagorean Quadruple
• Reflection Triangle
• Regular Tetrahedron
• Right Triangle
• Second Yff Circles Triangle
• Simson Line
• Soddy Line
• Soddyian Triangle
• Space Division by Spheres
• Spherical Excess