How do you determine the number of possible triangles and find the measure of the three angles given #a=8, b=10, mangleA=20#?
1 Answer
Explanation:
Since the given information is for a SSA triangle it is the ambiguous case. In the ambiguous case we first find the height by using the formula
Note that A is the given angle and its side is always a so the other side will be b .
So if

#h < a < b# then then there are two solutions or two triangles. 
#h < b < a# then there is one solution or one triangle. 
#a < h < b# then there is no solution or no triangle.
If

#a > b# then there is one solution or one triangle. 
#a <=b# there is no solution
Now let's use the Law of Cosine
quadratic formula
That is,
To find the measures of angle B we use the law of cosine and solve for B. That is,
and therefore
and therefore