A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 450
readily accomplished byconstructing in each case aright-angled triangle whose baseis equal to the length of anyforeshortened line in the plan,and its altitude to the verticalheight of the same line, as shown in the elevation. Thehypotenuse of such a triangle will then be equal to the truelength of… … 52 DEVELOPMENT OF SURFACES §10
