[tex]S\frac{O}{H}C\frac{A}{H}T\frac{O}{A}[/tex] or [tex]Sin\frac{Opposite}{Hypotenuse}Cos\frac{Adjacent}{Hypotenuse}Tan\frac{Opposite}{Adjacent}[/tex]
The hypotenuse is the longest side of the triangle.
The opposite side is the side across from a point/angle.
The adjacent side is the side next to the point/angle.
To find BC, you can do this:
tan 40° = O / A
tan 40° = [tex]\frac{BC}{15}[/tex] Multiply 15 on both sides
15(tan 40°) = BC
12.6 = BC
BC = 12.6 cm
