Answer:
There are 1849 tiles on the whole wall.
Step-by-step explanation:
If there are 85 tiles along the two diagonals, we can use the following rule:
So we have 43 tiles in the first diagonal and 85-43 = 42 in the second diagonal.
Now, as we have a square the side will have 43 tiles so the total area will be cover with:
Therefore, there are 1849 tiles on the whole wall.
I hope it helps you!