PROBLEM VIII. _To form an octagon, or eight-sided figure._
Refer back to _Fig. 5_. Draw the radius I, E, till it meets the
circumference at E. Join the points E, A, and E, B. Repeat this at each
of the four sides, and the octagon is formed.
The Architectural Review and American Builders' Journal, Aug. 1869 · 第 31 / 43 题