Shear and Moment Diagrams - Graphical/Integration method

[@dafinch221]

thank you so much this is the first explanation that has made since

[@engineeringpage4994]

how did you get the 67.5 in the bending moment

[@Okchan2]

Area of triangle （45x3）/2

[@zoiladeleon9978]

where is the 65 from

[@gamaltk]

Where is the integration method here?