Lesson 5: Polygons: Inscribed vs. Circumscribed (Plate 2-5)
Duration of Days: 2
Lesson Objective
Students will construct hexagons and octagons using the POLYGON tool, differentiating between "Inscribed in Circle" and "Circumscribed About Circle."
If you measure a bolt "across the flats," are you using an inscribed or circumscribed polygon?
How does the radius of the "imaginary circle" define the size of the polygon?
Polygon, Inscribed, Circumscribed, Across Flats, Across Corners.
CT CADD.05.03: Use drawing commands to create geometric shapes.
Students tackle Plate 2-5, creating various hex-head bolts and nuts. They will experiment with the two sub-settings of the POLYGON command to see which one aligns with the dimensions provided in the technical print.
Purpose: To master the construction of fasteners and specialized mechanical shapes.
DOK Level: 3.
Provide a physical hex-bolt and a caliper; have students measure it and determine if the CAD command should be "Inscribed" or "Circumscribed" to match the physical tool size.
Successful completion of Plate 2-5 with polygons sized correctly.
CAD Book - Basic Mechanical Drafting 2-5.