1. a number d is more than 0 and less than 10.

Sin  ф=opposite / hypotenuse
tan  ф=opposite / adjacent.
cos  ф=adjacent /hypotenuse.

in this case:
sin yº=a/6

opposite=a
hypotenuse=6

tan yº=a/b

opposite=a
adjacent=b



cos yº= adjacent /hypotenuse=b/6

answer: cos yº=b/6

1.3 and 1 1/3 are both closest to 1. hope this ; )