Help with this please!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer:
m∡A = 41.4°
m∡B = 48.6°
m∡C = 90°
a = 3[tex]\sqrt{7}[/tex]
b = 9
c = 12
Step-by-step explanation:
to find the length of side 'a' I used the Pythagorean Theorem to get:
a² + 9² = 12²
a² + 81 = 144
a² = 63
a = [tex]\sqrt{63}[/tex] which equals [tex]\sqrt{9}[/tex][tex]\sqrt{7}[/tex] which is 3[tex]\sqrt{7}[/tex]
to find m∡B I found the arcsin(B) = 9/12 to get 48.6
to find m∡A I subtracted the sum of 90 + 48.6 from 180°