Answer:
If
tan
(
�
)
=
�
�
tan(x)=
N
M
and
tan
(
�
)
=
�
�
tan(y)=
M
N
, then it must be true that
�
+
�
=
9
0
∘
x+y=90
∘
or
�
+
�
=
27
0
∘
x+y=270
∘
. This is because the tangent function is positive in the first and third quadrants, where the sum of angles is either 90 degrees or 270 degrees
1
2
.
