Answer:
Option B 7sqrt2
Step-by-step explanation:
I assume that in the right triangle y and 7 are the legs and x is the hypotenuse
so
we know that
In the right triangle
cos(45)=7/x ----> the cosine of angle of 45 degrees is equal to divide the adjacent side to angle of 45 degrees by the hypotenuse
In this problem y=7 because is a 45-90-45 triangle
Remember that
cos(45)=√2/2
equate the equations
√2/2=7/x
x=14/√2
x=14/√2*(√2/√2)=14√2/2=7√2 units
