How do schools measure the 'shortest straight line'?

[mypersonalstylist]

We have been refused a place at our local school due to being too far away. The school prospectus says that they measure the 'shortest straight line' between the school and our house. Can anyone confirm that this means 'as the crow flies' rather than safest walking distance? And how can we measure this ourselves to double check the figures????!!!!
THis is for Rosendale Primary in SE21 which is massively oversubscribed.....

You could try using Google Earth; that allows a point-to-point measuring tool, not just postcode. You can ring up the council and check their measurements and obtain a map (they have to comply with all reasonable requests for data for a school appeal).

Our Council used a shortest-route measurement that we argued was wrong, as there was a barrier at the turn-off they used, and another route (without a barrier) was shorter.

Will you win using Class Size Prejudice? (under 30 kids)?