Sec3- A Math Trigonometry-Proving by Gary Ang | Aug 16, 2015 | 16S4, Board-casts | 0 comments [vimeography id="262"] In this lesson, we practised more questions on trigo proving. Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website Save my name, email, and website in this browser for the next time I comment. Δ