(i) An ice-cream cone (ii) a cricket ball (iii) a glass tumbler (iv) a brick (v) a star
Which of the above are polyhedrons?
iv, v
A polyhedron is a three-dimensional shape having polygons as its faces usually joined by edges.
An ice cream cone is in the shape of a cone. A cricket ball is in the shape of a sphere. A glass tumbler has the shape of a cylinder. Cone, sphere, cylinder have curved surface and therefore do not have edges. So they do not come under the category of polyhedrons.
A brick has the shape of a cuboid. A cuboid has rectangular faces and no curved surface. A star also has no curved surface. So iv, v are polyhedrons.