Write down the number of edges of each of the following:
(a) a triangular prism
(b) a sphere
(c) a square pyramid
(a) Number of edges in a triangular prism = 9
(b) Number of edges in a sphere = 0
(c) Number of edges in a square pyramid = 8
(b) Number of edges in a sphere = 0
(c) Number of edges in a square pyramid = 8