image/svg+xml
y
x
atan(1) = 45°
atan(1/2) = 26.57°
atan(1/4) = 14.04°
x
y
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-
+
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
0
-
+
0
0
0
1
1
0
0
0
0
0
0
0
1
0
0
0
0
0
1
0
0
0
0
0
0
1
1
0
0
0
0
0
-
+
0
0
0
0
1
0
0
0
0
1
1
0
1
0
0
0
α
+45°
0
+26.57
45°
+14.04
71.57
85.61