Full Definition of DUSKY. 1. : somewhat dark in color; specifically: having dark skin. 2. : marked by slight or deficient light: shadowy. â duskÂ·iÂ·ly \-kÉ-lÄ\ adverb. â duskÂ·iÂ·ness \-kÄ-nÉs\ noun. See dusky defined for English-language learners.See dusky defined for kids. ADVERTISEMENT.ull Definition of DUSKY. 1. : somewhat dark in color; specifically: having dark skin. 2. : marked by slight or deficient light: shadowy. â duskÂ·iÂ·ly \-kÉ-lÄ\ adverb. â duskÂ·iÂ·ness \-kÄ-nÉs\ noun. See dusky defined for English-language learners. See dusky defined for kids.
A prism is a three-dimensional figure with two parallel congruent faces, called bases, and lateral faces in the shape of parallelograms. Prisms are named according to the shape of their bases. A prism whose bases and lateral faces are rectangles. A rectangular prism whose faces are squares. A three-dimensional shape with two parallel congruent circular faces whose cross sections (taken parallel to these circular faces) are circular. A cone is like a pyramid with a circular base.
A traditional triangular prism is a solid figure which is made up of two triangular bases and three rectangular faces. The two triangular bases face each other and are joined together with the help of three rectangles. Triangular prism is the most useful prism in geometry as well as in optical physics.