can use right angle angle trigonometry as this is a right triangle
sine is opposite over hypotenuse
sin 60 = BC/AB because opposite to 60 is BC and the hypotenuse is AB.
rearrange for AB
sin 60 = BC/AB
AB sin 60 = BC
AB = BC / sin 60
we are given that BC = 15 in
AB = 15 / sin60
AB = 17.321 in (calculator
can use tangent of 60 degrees to find AC
tangent is opposite over adjacent so
tan(60) = BC / AC
AC tan 60 = BC
AC = BC / tan 60
AC = 15 / tan 60
AC = 8.660 in
