A4 is standard typing paper size (so approx 30 cm long by 21 cm wide, or
12" x 81/2") and A3 is twice that at 42cm long by 30cm wide.

I hope your Durham has got better weather than we have! We had a severe
weather warning out last night, gales and pouring rain still going. I'm
going to get soaked but we've got to go out as DS is going to a friends
birthday party and I haven't got a present yet. Any idea what 2 yr old
girls like?

Sarah