1. The isogonal conjugates of the Fermat points are the isodynamic points and vice versa .
2. The isogonal conjugates of the fermat points are isodynamic points and vice versa .
OPTIONS:
- no
- yes

yes

1. The first three floors were completed in 1885 , the three upper floors were completed in 1906 .
2. The three upper floors were completed in 1885 and the first three floors were completed in 1906 .
OPTIONS:
- no
- yes

no

1. After Sutherland 's death in 1950 , further issues of the book were published by Cressey and D. F. Luckenbill as co-authors .
2. Further editions of the book were published by Cressey and Sutherland as co-authors after the death of D. F. Luckenbill in 1950 .
OPTIONS:
- no
- yes
no