sinA= 2/3
cosA= √(1-(sinA)^2) =√(1 -4/9) =√(5/9) =√5/3
tgA= sinA/cosA =2/3 :√5/3 =2/√5 =2√5/5
ctgA= 1/tgA =√5/2
sinA= 2/3
cosA= √(1-(sinA)^2) =√(1 -4/9) =√(5/9) =√5/3
tgA= sinA/cosA =2/3 :√5/3 =2/√5 =2√5/5
ctgA= 1/tgA =√5/2