Question 1456
I think that 19th century means 18xx right??? because year 0 is count as first century...
So we can use guess and check, see th square of a number is equal to 18_ _
I used a calc and found out that only 43^2 whcih is 1849 is equal to 18_ _
so 1849 - 43 = 1806 whcih is the year he was born in, I hope it is right