The human brain is the most important organ of the human body. It controls our thoughts, movements and emotions. For that reason, protecting the brain from harm is of the utmost importance but to protect the brain, one must first understand brain injuries. Currently, observations and criteria involving brain injury are focused around acceleration and forces. However, the brain is poorly understood in the frequency domain. This study uses finite element analysis to simulate impact for 5 different impact angles. Then a numerical technique called dynamic mode decomposition is used to extract modal properties for brain tissue in regions near the corpus callosum and brain stem. Three modal frequencies were identified with frequency ranges of (44-68) Hz, (68-155) Hz, and (114-299) Hz. Additionally, it was observed that impact angle, displacement direction, and region of the brain have a significant impact on the modal response of brain tissue during impact.