Measure great distances in the sky with your hand !
Extend your arm and point your little finger. You can measure the distance and the apparent size of an object equivalent to 1°
If you extend your arm and raise three fingers, you can measure a distance between objects or the apparent size of an object of 5°
Your fist is about 10°. If you extend your arm and your fist fills the distance between Jupiter and the Moon, then it is 10°.
Extending your arm in front of you and unfolding your fingers, you can measure a distance of about 20°.