Aeroplanes over High Pike again

Ah! The joy of going up High Pike again in the company of a smart phone owner. When first spotted the Airbus was at 31000 feet and over Ullswater.

By the time I took this photo it was down to 29000 feet.and half way between us and the motorway. 29000 is 9.4km. Half way to the motorway is about 10km. By Pythagoras, that about 14km away. The plane is about 70m long. Angle subtended is 70/14000 = 0.005 radians. That's 0.3 of a degree. If my finger is worth 1 degree, then the plane is worth ... well, I've blown up the image and it is 2/12 = 0.2 of a degree. Not too bad.