BASE, AND ITS MODIFICATIONS. 153 



Class h. Obtuse lateral solid angles replaced by 

 two planes, resting on the edges of the pyramids. 



Class i. Obtuse lateral solid angles replaced by 

 two planes, resting on the edges of the base. 



Planes i might be the lateral planes of a right 

 rhombic prism. 



Class k. Obtuse lateral solid angles replaced by 

 four planes, resting on the primary planes. 



The edges produced by the intersection of the 

 planes of this modification with the primary planes, 

 are parallel to the primary edges of the pyramids. 



