## height of the triangle over the vectors

I really need help with this task:

Determine vector of height $h_a$ from top A in triangle ABC if $\vec BC$ $=$ $\vec m$ $+ 2*\vec n$ and $\vec CA$ $= 2* \vec m$ $- \vec n$ $|\vec m | = | \vec n | = \sqrt 3$ and angle between vectors $\vec m$ and $\vec n = \pi/2$.