Abcd is rotated counterclockwise about the origin. By how many degrees was abcd rotated?

The rotation is 270 degrees counterclockwise

Step-by-step explanation:

Given

See attachment

Required

Degrees of rotation

From the question, the rotation is counterclockwise

Using point B and B' as points of reference.

The rule that supports the above is: rotation by 270 degrees counterclockwise.

Because the rule is:

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47