You should be OK with a 145cm screen at that distance. Calculations are as follows using the 145:
Minimum throw distance is 9.51 feet (2.9m) - Maximum 11.4ft (3.48)
If you have a look at our US website you will see the new H30, H56 & H76. On the site you can use the online calculator to find the throw distance or screen size. Always allow app +/- 5% tolerance on the calculations. I hope this helps.
You can find it at
www.optomahometheater.com
Regards