4.Development of a right circular cone

The development of a cone is shown in figure 4.  For a cone, the front view will be a triangle with the slant edge showing the true length  of the generator of the cone. To begin this development, use a true-length element of the cone as the radius for an arc and as one side of the development.  Draw an arc whose length is equal to the circumference of the base of the cone. This can also be determined by angle θ = (r/l) * 360°, where, r is the radius of the base of the cone and l is the true length of the slant edge. Draw another line from the end of the arc to the apex and draw the circular base to complete the development.  

 

 

Figure 4.  Development of a right cone.