Kindly look at the attached past paper question from British A Level Mathematics.

1) What I want to know is that since it doesn't state in the question whether to calculate the values of the sectors and arc lengths by using the angles in degrees or radians, if I calculate my answers with angles in degrees (since in the question an angle, 90, is already given in degrees) would my answers be correct/acceptable?

2) Do we always calculate the values in such sector based questions based upon radians or does the examiner define whether to use degrees or radians.