math/ geometry.
posted by Juleana .
the vertex angle of an isoceles triangle is 120. the base length is 18. what is the length of the altitude to the base in simplest form

tan(120°/2)=(18/2)/h
tan(60°)=9/h
h=9/tan(60°)=9*ctg(60°)
h=9/sqroot(3)
9=3*sqroot(3)*sqroot(3)
h=3*sqroot(3)*sqroot(3)/sqroot(3)
h=3*sqroot(3)
h=5.1961524227