If you make this picture bigger, you will see a small white dot just to the left of my little finger. That's a plane high over Wigton heading for America. Imagine a triangle from one side of my little finger down to the camera lens and back up to the other side of my little finger. The camera was about 60 cm from my little finger. Show that the angle in the triangle is about 1 degree.
So my little finger represents an angle of about 1 degree when held at arm's length. Compare my little finger to the plane. If my little finger is worth 1 degree, what is the plane worth?
Find out how big an aeroplane and use the triangle idea to calculate how high the aeroplane is.
