SinA=5/13
if it is a right triangle we can use the Pythagorean theorem to solve for the missing side. 13 = hypotenuse, and 12 = a leg.
[tex]a^{2} +b^2=c^2[/tex]
Plug in values
[tex]12^{2} +b^2=13^2[/tex]
subtract 12 squared from both sides
[tex]b^2=13^2 -12^{2} [/tex]
[tex]13^2 -12^{2} =25
[/tex]
squared root of 25 is 5. the missing leg is 5 so sin is opp/hyp or 5/13
