Here is a set of free short videos for stepwise preparation of Geometry on GMAT. For a more detailed treatment of the topic, you may want to opt for our GMAT online course or our GMAT test series of 15 mock tests.
Angles - Lines
Angles - Triangles
Angles - Polygons
Basic Properties of Triangles
Basic Properties of Quadrilaterals
Basic Properties of Isosceles, Equilateral, and Right Triangles
Basic Properties of Circles
Basic Properties of Congruent and Similar Traingles
GMAT's Favorite Right Triangles
An Interesting Question Type on Triangles
Another Important Question Type on Triangles
Area of Overlapping Regions I
Area of Overlapping Regions II
Difference Between Prism and Pyramids
How to Find "Curved Surface" Area of Any Solid
How to Find "Total Surface" Area of Any Solid
How to Find the "Volume" of Any Solid
Properties of Sphere and Hemisphere
An Important Concept on Solids