you really didn't give us enough information...so
were you on radar vectors, and had been given a heading to intercetp?
were you in radar contact?
were you in VMC DAYLIGHT?
What kind of final/instrument approach were you intercepting, a localizer, vor , ndb? four course range?
One could determine a 10 mile final by cchecking glide slope indications by adding 3200 feet to touchdown zone elevation (actually closer to 3160 feet)...so, fly at 3200' and when GS is centered, you are about 10 miles (slant range to GS antenna).
So, what exactly is the info as req'd above?
oh, did you have the airport in sight? had you been to the airport before?