# Maths - Vectors

posted by
**Claire**
.

The position vectors a,b,c of the points A,B,C relative to the origin O are ai, bj and ck respectively.Find:

1) a vector equation for the line l throught O which is normal to the plane ABC.

2) a vector equation of the plane ABC

The answers should be:

1) r=t(bc i +ac j +ab k) and

2)r.(bc i +ac j +ab k) = abc

Can someone please explain how to work this question? Thanks!