Measuring a plot from an HM Land Reg map

[silverdale]

Anyone any good at measuring a plot of an HM land registry map scale 1:625 ? I am trying to figure out the sq "yards" from a deeds title. I've tried google but too many trees to know exactly were the fencing is. I have a measured it I just wanted to know if yours tallys up with mine.

I need both A and B on there own then A + B combined maths isn't my best subject unless it involves ale and a bar