I have always had problems with vectors and now need help to understend this simpe task:

Given triangle ABC with vertices A(-2; 5), B(-5; 4), C(1;1).

Find:

1)vecto coordinates and length

2) internal angle to vertice B

3) general equation of line AB

4) general equation of height CD

5)edge AB and height CD intersection D

For 1st I think that