Introduction to Triangulation

The triangulation method used for developing is the most versatile , as it is possible to do any development with triangulation , and in fact , as there are many developments that can only be done by triangulation .It is therefore of the utmost importance to understand the basic principles of triangulation
Triangulation theorem
Rule:To obtain the true length of a line , take the plan length and place , normal to the wertical height between the points considered
example:
(a) Draw a vertical line with height corresponding to vertical height of the other shape eg cone
(b)Take plan length of XY and place normal to the vertical line drawn to represent the vertical height
(c)Now set compass to the length across the hypotenuse of the triangle formed thus .This will represent the true length x.y (check with front elevation )
We can summarise this rule as follows :THE PLAN LENGTH AGAINST THE VERTICAL HEIGHT AND MEASURE THER SLANT LENGTH WHICH IS THE TRUE LENGTH
THE MAIN POINTS TO OBSERVE
(a)Draw neatly and accurately
(b)Plan view is of most importance
(c)Draw front elevation (d)Determine the bend lines
(e)Number each plane differently ir bottom plane A,B,C etc and top plave 1,2,3 etc
(f)Calculate the circumference and obtain unit length (circumference+12)
(g) Obtain true lengths
(h)Start developing on the opposite side of the required joiint and work symmetrical about the starting points
(i)As you complete each seccesive triangle mark the points and draw the appropriate lines
NOTE :by numbering the two planes different ly , you immediately know which dimensions taken from the plan are true and for which we should find the true lengths .Measuring between A , B, Cetc and 1,2,3 etc , will be true lengths , whereas if we measure from the letters to numbers we have to find the true lengths
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