Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Geometry
Practice using your graphing calculator for geometry problems, including the use of the Pythagorean Theorem and the distance formula. If you get stumped or if you would like to check your work, then select the View Solution button, which...
Khan Academy
Khan Academy: Parallel & Perpendicular Lines From Equation
Use your knowledge about the slopes of parallel and perpendicular lines to solve some problems. For example, what's the equation of the lineperpendicular to y=3x-3 and passes through the point (-8, -2).
Texas A&M University
Wtamu Virtual Math Lab: Beginning Algebra: Slope
A tutorial on slope with many step-by-step examples. The tutorial clarifies what slope is, how to find slope between two points on a graph, and how slopes of parallel and perpendicular lines are related.