Answer:
Step-by-step explanation:
in a right angled triangle
c^2=a^2+b^2
b^2=c^2-a^2
b=√(c²-a²)
or b=√(13²-7²)
=√(169-49)
=√(120)
=2√(30)
by sin formula
[tex]\frac{sin A}{a}=\frac{sin B}{b} =\frac{sin C}{c} \\\frac{sin A}{7}=\frac{sin B}{2\sqrt{30}} =\frac{sin 90}{13} \\\frac{sin A}{7}=\frac{sin B}{2\sqrt{30} } =\frac{1}{13} \\sin A=\frac{7}{13} \\A=sin^{-1} (\frac{7}{13} )\approx 33.6^\circ\\B=90-33.6\approx 56.4^\circ[/tex]
