Question

A= 225° is written in rectangular form as...
y = 1
y = -1
y = x
y = -x

Answer 1

A = 225° in rectangular form

is written as x = cos (225) = -0.707
                    y = sin (225) = -0.707

The answer is y = x

This angle is in the third quadrant,  x and y have the same amplitude and both are negative.