D) construction of the angle bisector.
So if you have a triangle that is not equilateral the perpendicular bisectors would not work so you need angle bisectors.
I have drawn a diagram
The green is the angle bisectors and the yellow the perpendicular bisectors.
You can see the problem straight away
The greatest six-digit number they could make is 998,877 I know this because I used the largest digits and put them in order from largest to smallest.
Hope this helps
Answer:
⣠⣴⣶⣿⠿⢿⣶⣶⣦⣄⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⣼⡿⠋⠁⠀⠀⠀⢀⣈⠙⢿⣷⡄⠀⠀ ⠀⠀⠀⠀⢸⣿⠁⠀⢀⣴⣿⠿⠿⠿⠿⠿⢿⣷⣄⠀ ⠀⢀⣀⣠⣾⣿⡇⠀⣾⣿⡄⠀⠀⠀⠀⠀⠀⠀⠹⣧ ⣾⡿⠉⠉⣿⠀⡇⠀⠸⣿⡌⠓⠶⠤⣤⡤⠶⢚⣻⡟ . ⣿⣧⠖⠒⣿⡄⡇⠀⠀⠙⢿⣷⣶⣶⣶⣶⣶⢿⣿⠀ . ⣿⡇⠀⠀⣿⡇⢰⠀⠀⠀⠀⠈⠉⠉⠉⠁⠀⠀⣿⠀. ⣿⡇⠀⠀⣿⡇⠈⡄⠀⠀⠀⠀⠀⠀⠀⠀⢀⣿⣿⠀ ⣿⣷⠀⠀⣿⡇⠀⠘⠦⣄⣀⣀⣀⣀⣀⡤⠊⠀⣿⠀ ⢿⣿⣤⣀⣿⡇⠀⠀⠀⢀⣀⣉⡉⠁⣀⡀⠀⣾⡟⠀ ⠀⠉⠛⠛⣿⡇⠀⠀⠀⠀⣿⡟⣿⡟⠋⠀ * ° * • ☆ ° .°• * ✯ ☄ ☆ ★ * ° * °· * . • ° ★ • ☄ ☄ ▁▂▃▄▅▆▇▇▆▅▄▃▁
⣠⣴⣶⣿⠿⢿⣶⣶⣦⣄⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⣼⡿⠋⠁⠀⠀⠀⢀⣈⠙⢿⣷⡄⠀⠀ ⠀⠀⠀⠀⢸⣿⠁⠀⢀⣴⣿⠿⠿⠿⠿⠿⢿⣷⣄⠀ ⠀⢀⣀⣠⣾⣿⡇⠀⣾⣿⡄⠀⠀⠀⠀⠀⠀⠀⠹⣧ ⣾⡿⠉⠉⣿⠀⡇⠀⠸⣿⡌⠓⠶⠤⣤⡤⠶⢚⣻⡟ . ⣿⣧⠖⠒⣿⡄⡇⠀⠀⠙⢿⣷⣶⣶⣶⣶⣶⢿⣿⠀ . ⣿⡇⠀⠀⣿⡇⢰⠀⠀⠀⠀⠈⠉⠉⠉⠁⠀⠀⣿⠀. ⣿⡇⠀⠀⣿⡇⠈⡄⠀⠀⠀⠀⠀⠀⠀⠀⢀⣿⣿⠀ ⣿⣷⠀⠀⣿⡇⠀⠘⠦⣄⣀⣀⣀⣀⣀⡤⠊⠀⣿⠀ ⢿⣿⣤⣀⣿⡇⠀⠀⠀⢀⣀⣉⡉⠁⣀⡀⠀⣾⡟⠀ ⠀⠉⠛⠛⣿⡇⠀⠀⠀⠀⣿⡟⣿⡟⠋⠀ * ° * • ☆ ° .°• * ✯ ☄ ☆ ★ * ° * °· * . • ° ★ • ☄ ☄ ▁▂▃▄▅▆▇▇▆▅▄▃▁
8 : 4
16 : 8
4 : 2
Simplest:
2 : 1