Explanation:

Gandhara school of art - has Greco-Roman elements in the treatment of sculpture. The Buddha head has typical Hellenistic elements that have grown over a period of time. The curly hair of the Buddha, the forehead plane is large having protruding eyeballs, the eyes are half-closed and the face and cheeks are not round like the images found in other parts of India. There is a certain amount of heaviness in the figures. The ears are elongated especially the earlobes. The treatment of the form bears linearity and the outlines are sharp. The surface is smooth.
Sarnath school of sculpture - the body is slender and well-proportioned but slightly elongated. The outlines are delicate, very rhythmic. Folded legs are expanded in order to create a visual balance in the picture space. Drapery clings to the body and is transparent to create the effect of integrated volume. The face is round, the eyes are half-closed, the lower lip is protruding.
Mathura School of art - There is boldness in carving the large images, the volume of the images is projected out of the picture plane, the faces are round and smiling, heaviness in the sculptural volume is reduced to relaxed flesh. The garments of the body are clearly visible and they cover the left shoulder.