Remember that if in a triangle [tex] \alpha \ \textless \ 90[/tex]°and [tex]bSin \alpha \ \textless \ a\ \textless \ b[/tex], we can form two tingles.
In our case: [tex] \alpha =B[/tex], [tex]b=a[/tex], and c=b.
To determine how many triangles we can form with the given measures, we are going to find the value of [tex]cSinB[/tex] first:
[tex]8.9Sin(63)=7.9[/tex]
Now, lets check if that value satisfy the inequality [tex]cSinB\ \textless \ b\ \textless \ c[/tex]:
[tex]7.9\ \textless \ 10\ \textless \ 8.9[/tex]
Our triangle satisfies the inequality; therefore, we can conclude that we can form two triangles with the given measures.
