
https://www.questionsolutions.com/wp-content/uploads/2016/11/ptt2.png
https://www.questionsolutions.com/wp-content/uploads/2016/11/ptt5.png
Image from: Hibbeler, R. C., S. C. Fan, Kai Beng. Yap, and Peter Schiavone. Statics: Mechanics for Engineers. Singapore: Pearson, 2013.