cortana what is the meaning of diameter what is a diameter
d = 2 r â r = d 2 . {\displaystyle d=2r\quad \Rightarrow \quad r={\frac {d}{2}}.}. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the width is defined to be the smallest such distance.