BBC
Bbc: Angles
You can pick up some valuable pointers on angles and lines here. When you finish working your way through the pages you can take an on-line "Test Bite," and check your understanding.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Angle Basics
Find a quick, concise explanation of angles and types of angles. Several examples are given to help you understand how angles are formed and the different types of angles.
University of Cambridge
University of Cambridge: Nrich: Angle A
Sharpen your logic and angle recognition skills by working on this interactive challenge. Solution available.