A triangle with 45 degrees on one corner and 90 degrees on another has 45 degrees on the third corner (180-side1-side2=side3). Therefore that’s an isosceles triangle, which has the same length on the two sides next to the right angle. To get the length of the third side, remember that for any right triangle, the longest side is equal to the square root of :(the first side squared)+(the second side squared). A^2+b^2=c^2 or c=sqrt(a^2+b^2). If you do the math, sqrt((7sqrt2)^2+(7sqrt2)^2)=14. That’s your third side length, x=14.