give two reasons for formation of shadow on what factor does the sharpness of the shadow depends

Dear student, Shadow is formed because an obstacle comes in the path of light rays that blocks it's passage and form a dark region known as shadow. Second reason is that when any object intentionally or unintentionally comes into the path of light so light rays are unable to pierce the object and hence it's shadow is formed................... Second part, two factors affecting the size and sharpness of shadow are distance from the light source and the size and type of light source. Regards