sin ^2 (a) =1 - cos ^2(a) = 1- 9/25 = 16/25
sin a= 4/5
tga = sina/cosa= 0,8/0,6= 4/3
ctga= 1/tga= 3/4
sin ^2 (a) =1 - cos ^2(a) = 1- 9/25 = 16/25
sin a= 4/5
tga = sina/cosa= 0,8/0,6= 4/3
ctga= 1/tga= 3/4