Notice that the given right triangle has a marked angle measuring 45^(∘). Therefore, by the Triangle Angle Sum Theorem the measure of the third angle must also be 45^(∘).
In a 45^(∘)-45^(∘)-90^(∘) triangle, the legs are congruent and the hypotenuse is sqrt(2) times the length of a leg. With this information, we can find the value of each variable.
x= sqrt(2) * 9sqrt(2)
Finally, we can find the simplest expression for x.
