The specific lesson or activity labeled as "1.2.3" would depend on the course and the year it is being taught. PLTW courses are structured into modules or units, each with specific learning objectives. For example, in the Introduction to Engineering Design course, units might focus on design process, reverse engineering, and prototyping.
A method of creating 2D views from a 3D object while maintaining scale and proportion. pltw 1.2.3