My mum found these round cork boards at an op shop but I remember seeing a similar DIY in Real Living some time ago using embroidery hoops and Avskild cork mats from Ikea which you can simply trace around and cut into a circle in order to complete this project.
Paint or spray paint in two colours
Stippling sponge to create the polka dot pattern
1.To make the geo painted board simple tape in half and spray or paint one side
2. When that is dry tape a line across the painted side skimming the edge as shown below and then place another piece of tape horizontally about a third of the way up to create a triangle shape then paint with your contrasting colour and that is it!.
For the polka dot board simple take your paint covered stippling brush and stamp your dots around the board.