Use special right triangles to solve for the exact value of x.
a- 7
b- 7sqrt2
c- sqrt of 14
(couldn't copy image so ill describe)
right triangle with x, y, 7 being side and 45 degrees for an angle

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

if you explain the the question more correctly i might be able to answer this better

step-by-step explanation: