1) cosA= √1-(sinA)^2= √1-3/4=1/2
2) sinB=cosA= √173/371
3)sinB=cosA= √1-(sinA)^2= √1-16*11/225= √225-176/225=7/15
4)tgA=sinA/cosA. sinA= √1-(cosA)^2= √1-2/16= √14/16= √14/4. tgA= √14/4*4/ √2 = √7
5)ctgB=cosB/sinB. cosB=sinA=5/ √41. sinB= √1-(cosB)^2= √1-25/41=4/ √41
6)ctgB=tgA=5/ √41
7)tgB*ctgA=tgB*tgB. sinA= √1-(cosA)^2= √1-0.6^2= √1-0.36=0.8. tgA=0.8/0.6=4/3. tgB*ctgA=4/3*4/3=16/9
8)sinA= √1-(cosA)^2= √1-0.36=0.8. tgA=0.8/0.6=4/3. AC=BC/tgA=12*3/4=9
9)cosA= √1-(sinA)^2= √1-4*10/121=9/11. AB=AC/cosA=15*11/9=55/3