1 Introduction , 1 2 Standardization (2-20): 2.1 Standard size of drawing sheet , 2 2.2 Standard lettering , 7 2.3 ISO draft , 15 2.4 Standard scales , 18 3 Geometric Construction , 21-29 4 Principle of Orthographic Projection (30-34): 4.1 ISO Projection symbol , 31 4.2 First angle projection , 31 4.3 Third angle projection , 33 5 Pictorial Presenta…