Răspuns:
Explicație pas cu pas:
In Δ ABC AC²=AB²+BC²=144+25=169 AC=13 cm
sin α=AB/AC=12/13
cosα=BC/AC=5/13
tgα=AB/BC=12/5
ctgα=BC/AB=5/12
ex 2 ΔDKR DK²=KR²-DK²=17²-15²=2·32=2^6 DK=2³=8 cm
sin β=DK/KR=15/17
cos β=DR/KR=8/17
tg β=DK/DR=15/8
ctg β=DR/DK=8/15
