2D shapes are the easiest way to create rectangles, circles and ellipses. Available in the Sketch menu, tap on the shape you need and start placing them with your Pencil.
Create a circle by tapping on the Circle tool. Put down the tip of the Pencil on one point and start dragging. You will notice that a Circle appeared. Once you are done, tap on the dimension label to define its radius.
Create an ellipse by tapping on the Ellipse tool. Same as with the Circle, just put the tip of the Pencil down and start dragging. Once you are done, you can define the major and the minor axis as well.
In Shapr3D an ellipse is defined by its center point, its major and its minor axis.
There are two ways to create/define a rectangle, one is by its center point and one is by its diagonal.
You can switch between the different methods by tapping on the Rectangle icon again. A modal will pop up, allowing you to choose:
Define a rectangle by it's diagonal. Just drop your pencil at a point and start dragging. You'll drag the opposite side of the diagonal. When you are ready, just lift your Pencil. Define the dimensions once you are done.
Center point rectangle
Define a rectangle by its centerpoint. Start by putting down your Pencil, where you want your Center point to be, and lift the Pencil when you are happy with the result. Define the dimensions once you are done.
Three point rectangle
Define the first side, and then put down the third point to define the second side's length.