sub panel
 

i want a new 100 amp sub panel for an addition i was thinking of running three #1 coppers, a black, red, and white, and a #8 green ground, but i do not know what type of insulation thhn or what, and is 1- 1/4 emt suitable i would run the pipe inside

How far away is this subpanel? By code, you would only need to run #3's CU to a 100A sub. If you are increasing the wiresize due to voltage drop, you must increase the equipment grounding conductor the same percentage.

1 1/4" will be fine, but if you are pulling a long distance, you may want to upsize to 1 1/2" to make the pull easier. You need a insulation type that is rated for wet locations, THWN is what you should be looking for, however, most THHN you buy is dual rated THHN/THWN.

If this is a detached structure, don't forget the ground rods.

i thought #3 copper was rated for 85 amps and it is 60 feet away from main panel

You thought wrong, at least according the NEC. #3 CU will be fine for your installation.

isnt #3 rated for 85 amps its 60 feet from main panel

#3 THHN/THWN is rated for 100A

You are confusing the ratings of a NM cable assembly with the ratings for individual THHN/THWN conductors.