Without looking at star maps as a reference, you can estimate degrees of distance in the celestial sphere by using a couple of tricks.
In general, if you hold your hand in a fist vertically at arm’s length, it measures about 10° against the sky.
Looking from Earth, the distance between the two stars that point to the North StarMerak and Dubhe, which form the right side of the Big Dipper’s bowl, is approximately 5°.
Also, remember that your celestial meridian, the imaginary line arcing above your head from your northern celestial horizon to your southern celestial horizon, equals 180°, and that your zenith is at 90° from the horizon.
Stars within a constellation are light-years away from each other.
They appear to be visually connected only when viewed from Earth.