Website / app that helps with calculating angles?

[samosamo]

Hi All,

Another specific on, but people on here do have a wealth of information about all sorts!

I want to do a side extension that is full height up to the boundary. Planning have said it should be ok win it falls within the 45 degree rule, meaning I have to draw a 45 degree line from t he tip of the extension down to check it doesn't block too much light from the neighbour's window.

Does anyone know a free (or trial?) website that I can use to mock up my spec?

Please let me know if so!!!!

Do you have the measurements between your boundary and the neighbours house? I think I'd just draw it out to scale on graph paper but that obviously isn't the question you asked!

I thought that, but was being lazy!