I don't know what you've tried, and your example above seems quite simple, so you should be able to build this as follows
1) Assumption : Your data is structured as 2 rows of data only (you don't need a total, as Tableau can do this automatically).
2) Use a quick table calculation to create % of total (Quick Table Calculations - Tableau)
3) Use Show Me (top right), and select pie chart and it will create what you need, coloured by Type, putting the various fields on the right shelves. You can edit the colours to suit.
Hope that helps
Hi Henrik - any feedback on this? If my response helped resolve your problem, please mark as correct, so the thread can be closed down.