Page 55 - ENGINEERING DRAWING

48

3.5.3 Constructions

All construction lines should be in thin lines. After completion of the isometric
views, erase the unwanted lines and construction lines.

Example 1 :
Draw the isometric drawing of a rectangular prism of base 30 mm x 40 mm and

the height 60 mm.

Procedure :

➢ Draw the three isometric axes through the point `A'.
➢ Mark AB = 15mm, AD = 30mm and AH = 50mm representing the three sides of

prism.

➢ Draw two vertical lines parallel to the line AH through points B and D.
➢ Similarly draw two more lines parallel to AB and AD through point H.

➢ Mark G and E (the intersecting points). Draw lines parallel to GH and HE

through points G and E intersecting point is F.

➢ Draw lines parallel to AB & AD through points D and B respectively intersecting

at C.
➢ Join CB & CD with dash lines. Join F and C also with dash lines.

➢ Rub off the construction lines and complete the prism.

Figure 3.21 : Rectangular prism