Define shadow.

Hint:A shadow occupies a three-dimensional volume of space, but this is usually not visible until it projects onto a reflective surface. If there is more than one light source, there will be several shadows, with the overlapping parts darker, and various combinations of brightness.

Complete step by step solution:
A shadow is really just an area or region, when there's no light since an opaque object is obstructing light rays. The intensity and position of the source of sunshine affect the properties of the sort of shadow that's formed. for instance, allow us to consider the sun to be a light-weight source. When it's early morning or late afternoon, you'll notice that your shadows are elongated. But at noon, when the sun is true above your head, the shadow formed is brief and dark in nature.

Also, you would’ve noticed that at noon, the shadows formed are more defined in nature in comparison to late afternoon or early morning shadows which are slightly blurred with edges not defined alright. This is often because the sunshine source is wider during these times. Light sources are often either beginning or non-point sources. If it's to some extent a source of sunshine, then it forms an easy shadow called an umbra. If it's an extended light, the shadow is split into the umbra, penumbra, and ant umbra. they will even be wont to define levels of darkness, as is usually done when handling sunspots. Although shadows sew surfaces are mostly two-dimensional in nature, they will even be seen to possess a three-dimensional effect. For instance, when a shadow is so dense mist or fog, you'll observe this effect.

Note:Transparent objects sort of a glass sheet or water are those which permit light rays to undergo it. Opaque objects are solid objects sort of a brick or a wall that don't let any light undergo them. Such sorts of objects cast shadows.