16S3: AM Trigonometry lesson 11 - R formula by Gary Ang | Sep 4, 2016 | 16S3, Board-casts | 0 comments [vimeography id="658"] In this lesson, we discussed the R-formula. Submit a Comment Cancel replyYour email address will not be published.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