Edraw's flexible, handy drawing tools help quickly document a variety of complex structures, systems and processes. Besides, it knows what makes a diagram different from a drawing, and helps you create amazing diagrams quickly and easily. Customizable Grid and Snap tools help to position your shapes precisely. A number of Alignment, Distribution and Make Same tools will automate routine operations with multiple shapes. Unlimited number of layers is supported. Edraw software is intended for professional flowcharting, diagramming and illustrating. Its flexible, handy drawing tools help quickly document a variety of complex structures, systems and processes. In the library menu, you can use the drawing tools which contain all the tools you need to draw and edit your own shapes. To draw square, drag the mouse to 45 degree direction from the start point, the assistant line will appear, then snap mouse, drag mouse along the assistant line until the size you want. Note: Make sure that Drawing aids option is checked, otherwise the assistant line will never appear. To draw circle, drag the mouse to 45 degree direction from the start point, the assistant line will appear, then snap mouse, drag mouse along the assistant line until the size you want. After you draw the second segment, the shape displays vertices (vertex, vertices: One of the diamond-shaped handles that appears between two segments on a multiple-segment shape, or at the end of a segment. You can reshape a shape or connector by dragging its vertices.) instead of endpoints . The shape becomes opaque, indicating that it is a closed shape (closed shape: A shape that is surrounded by a continuous outline, such as a rectangle or circle. You can fill a closed shape with a color or a pattern.). Edraw Max is perfect not only for professional-looking flowcharts, organizational charts, mind maps, but also network diagrams, floor plans, workflows, fashion designs, UML diagrams, electrical diagrams, science illustration, charts and graphs... and that is just the beginning! Source.