Math Planet
Math Planet: Algebra 1: Radical Expressions: The Distance and Midpoint Formulas
Distance and midpoint formulas are explained through the use of examples and a video lesson. [1:58]
CK-12 Foundation
Ck 12: Geometry: Segments Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews how to measure the distance between two points and the Ruler Postulate. It also introduces congruency/congruent segments and midpoint.