Answer to Question 1
The instructor should evaluate the alphabet of lines for neatness, accuracy, and detail drafting techniques. Compare to Figure 3-23 on page 70.
Lines that are drawn thick include visible lines and cutting plane lines.
Lines drawn thin are hidden lines, dimension lines, extension lines, centerlines, and phantom lines.
Construction lines and guide lines are drawn very light so they are not reproduced when copied.
Answer to Question 2
Use one of these three methods:
Enclosing square method: Lightly sketch a square, marking the midpoint on each side. Lightly draw in arcs to connect the midpoints. Darken the final circle.
Centerline method: Lightly sketch horizontal and vertical center lines. Add light 45 radial lines and sketch arcs across them at estimated radius distances from the center. Darken the final circle.
Paper method: Mark the estimated radius on the edge of a card or scrap of paper and set off from the center as many points as desired. Sketch the final circle through these points.