15 Chapter 1 Introduction to Dimensioning and Tolerancing Copyright Goodheart-Willcox Co., Inc. The part from Figure 1-9 is shown again in Figure 1-10. However, the views are in positions based on fi rst angle projection. What was the top view in the previous fi gure is now beneath the front view instead of above it. It is important to determine whether ortho- graphic views have been created using fi rst or third angle projection. The importance should not be over- looked. There have been cases where the designer did not indicate the angle of projection, and the Front Right side Left side Top Bottom Back Third angle projection views Goodheart-Willcox Publisher Figure 1-9. Orthographic views shown in third angle projection. Front Right side Left side Top Bottom Back First angle projection views Goodheart-Willcox Publisher Figure 1-10. Orthographic views shown in fi rst angle projection.