Learn what Alternate Angles (Z-Angles) and Corresponding Angles (F-angles) are when dealing with Parallel Lines. Check http://www.explainingmaths.com for more maths help and FREE resource, activities and worksheets. This maths video will explain this IGCSE and GCSE mathematical topic to you by providing example questions. You can use these maths activities for your math revision to do better on your IGCSE GCSE exam paper.