In this paper, the usage of matrix in computer graphics is shown. A brief overview of geometric transformations in computer graphics is given. The "Matrix - Computer Graphics" application software is created for the representation and easier understanding of relations between geometric transformations and matrix calculus. We introduce and explore the basic matrix operation such as translation, rotation, scaling, reflection, shearing in 2D and 3D and at end we explain about the parallel and perspective view. These concepts commonly appear in video game graphics. The work has also shown some programming in using C/C++ code.