We wrapped up your area work (on the chart paper), and then learned to find an altitude given the coordinates of the vertices of a triangle.

If you have triangle with base , the altitude from can be found using the following steps:

Find the slope of

Find the slope of the altitude (negative reciprocal of the slope of since it’s perpendicular)

Find the equation of the line through

Find the equation of the altitude line

In the example we did today we also found the point which was the intersection of the altitude with the base. For that we needed to solve the system of equations for those two lines.