(a)
\The triangle side is and angle is
The laws of sines :
The angle is acute angle,
Recall the relation from the ambiguous case: .
If triangle has one solution and is an acute angle , then
and
.
and
.
Substitute ,
in
.
If triangle has one solution, then values of are
and
.
(b)
\If triangle has two solutions and is an acute angle , then
.
Substitute the corresponding value in above formula.
\.
Divide each side by .
Finally conclude that .
(c)
\If triangle has no solution and is an acute angle, then
.
Divide each side by .
Substitute and
in above expression.
.
(a) and
.
(b) .
(c) .