ITS MODIFICATIONS. 123 



Class b. Acute solid angles replaced by four planes 

 resting on the primary planes. 



The new figures would be contained within 24 

 isosceles triangular planes. 



Class c. Acute solid angles replaced by four planes 

 resting on the primary edges. 



The new figures would be contained within 24 

 trapezoidal planes. 



Class d. Acute solid angles replaced by eight 

 planes. 



The new figures would be contained within 48 

 triangular planes. 





Class e. Obtuse solid angles replaced by tangent 

 planes. 



The new figure would be the regular octahedron. 

 Plane e on P 144 44' S". 



