To draw a square, first draw a rectangle and then hold shift while dragging one of its corners to make it a perfect square shape. The same method can be used to draw a circle by first drawing an ellipse and then holding shift to drag it into a perfect circle.

1. Draw a rectangle for practice and then press shift and drag the rectangle to draw a square

2. The process is the same for drawing a circle , first draw a ellipsis and then get a circle by pressing
shift and dragging the shape