Passing through (-7,-6) and parallel to the line whose equation is y= - 3x + 2

How can you decide witch operations to use to slice a two step equation

Aperpendicular bisector, cd is drawn through point con ab if the coordinates of point a are (-3, 2) and the coordinates of point b are (7,6), the x-intercept of cd is point lies on cd.

The length of a shadow of the building is 36m. the length of the pole, which is perpendicular to the ground, is 1.9m. the length of the pole's shadow is 1.52m. what is the height of the building?