(sina+cosa)^2= 1/25

(Sina) 2+(COSA) 2+2 Sina cosa= 1/25

1+2 Sina cosa= 1/25

2 Sina cosa=-24/25

Sina cosa=- 12/25

(2) By (1)

Sina +cosa= 1/5

Sina cosa=- 12/25

Sina =4/5

cosa=-3/5

Obtuse triangle

(3)tana=sina/cosa=-4/3