The amount of sunshine, where the sun is, and if there is any sun at all.
The angle of the light hitting the tree if the sun is high in the sky the Shadow is short for example if the sun is directly over a post then the post will cast no shadow. as the sun moves into a position that causes its light to shine on the side of the post a shadow will appear on the opposite side of the post where it blocks the sun. as the sun seems to assume a relatively lower position compared to the horizon it will make the shadow longer and longer.
when you change the object that creates the shadow by blocking the light, its' shadow will change. or there is another light source shining from a different direction on the object will affect the shadow too.
The length of the shadow (on a flat, horizontal floor) depends on the height of the Sun. If the Sun is higher in the sky, the shadow will become shorter.
the position of the sun
The moon's shadow changes its placement due to the moon's orbit around the Earth and the Earth's rotation on its axis. This movement causes the moon's shadow to shift and change its position relative to the Earth.
The length of a shadow is primarily determined by the angle of the sun in relation to the object casting the shadow. Shadows are longer in the early morning and late afternoon when the sun is lower in the sky, and shorter at midday when the sun is directly overhead. The size and shape of the object casting the shadow also play a role in determining shadow length.
when you move and when the sun angle changes
Depending on which angle the sun is in relation to your body your shadows length can change.
Shadows change length based on the position of the light source. When the light source is higher in the sky, shadows are shorter, while when the light source is lower, shadows are longer. Additionally, the angle and distance between the object casting the shadow and the surface it falls upon can also impact shadow length.
The shadow is caused by the earth blocking the path of the light from the sun casting shadow on the moon. When the earth is not in between the sun and the moon then we have a "full moon."
The position and length of your shadow change throughout the day due to the angle of the sun in the sky. In the morning and evening when the sun is lower in the sky, your shadow will be longer. At midday when the sun is directly overhead, your shadow will be shorter.
Its shadow will be 50 millimeters in length, if you lay it down on a flat surface.
The shape does not change, only the length, depending on where the light comes from. Such as on a sundial, and the shadow gets longer or shorter over hours.