Since the smaller triangle is a right isosceles triangle thus the 2 sides facing the angle of 45 degrees are of same length and the side facing the right angle is of length 11 radical 2 ( this is a property you can memorize or apply Pythagoras’ theorem and find the length by BC^2= AB^2 + AC^2 ) and you’ll have the same answer.
After doing so, what is left is to find X, the second triangle has a right angle and a 60 degrees angle, thus it is a right equilateral triangle where the side facing an angle of thirty degrees is denoted by S and the side facing 90 is 2S and the side facing the angle of 60 degrees is S radical 3 ( You can also find those ratios if you know trigonometry where you can solve for sin(30) = opposite side/hypotenuse but I don’t know if you already have studied it ). So finally since X is facing the 90 degrees angle it is of length 2S = 2 multiplied by 11 radical 2 = 22 to the radical of 2.
To make it easier for you name both triangles ( denote by letters ) and then solve. ♥️