Basic marks, perspective

This drawings is a study of points, lines, curves, gradient and the principles of two-point perspective. Every single things here, such as points, straight lines, vertical lines, horizon lines, slope line, polygons, circles, curves and the gradients are the basic of observational drawing.Practicing with the basic mark helped to develop my personal basic drawing stills. And perspective is a realistic way of drawing object in three- dimension which begin with two vanishing points and a horizon line. I think the box that I drew is successful in showing the shape and the shading, the value of light and dark on the box is adequate. However, I think lines on the practices are not very precise, they are not straight lines. And also the circles are not look like circles. But on the other hand, I think I did quite well at the gradients, successfully show the changing between light and dark.