it just so happen that √2 is an irrational number, so any product with it as a factor, will yield an irrational number as well.
factoid: Ancient Greeks were scared of irrational numbers, and they steered clear from √2.
So you would find out what number in the 9 times tables goes into 25 and there's your answer x
ABC and CBH are right angles
DBC = 90 - 37 = 53
CBJ = 90 - 31 = 59
HBD = 180 - 37 = 143
or
HBD = 31 + 53 + 59 = 143 :)