.sin²a+cos²a=1
sin²a=1-cos²a=1-(10/17) = 1-225/289=64/289
sina=√(64/289) =8/17
tga = sina : cos = 8/17:(15/17) =8/15
ctga=1/tga= 10/8
.sin²a+cos²a=1
sin²a=1-cos²a=1-(10/17) = 1-225/289=64/289
sina=√(64/289) =8/17
tga = sina : cos = 8/17:(15/17) =8/15
ctga=1/tga= 10/8