jika sin x=2/3, maka nilai cotan (90 derajat-x)=

sin x = 2/3
sisi depan = 2
sisi miring = 3
sisi samping = √(3²-2²) = √5

ctg(90°-x) = ctg x
= sisi samping/sisi depan
= √5 / 2 = ½√5