This document discusses a study that used thresholding methods to determine the area of breast cancer from mammography images. Mammography images from three projections (oblique, lateral, cranial caudal) of patients with breast cancer were analyzed. The images were segmented using thresholding to separate the cancer area from the background. Morphological operations were also used to improve segmentation and remove noise. The calculated breast cancer areas for the three projections were 4.49 cm2, 3.03 cm2, and 2.58 cm2 respectively. Thresholding was able to accurately segment the images and calculate the cancer areas, aiding medical professionals in diagnosis and treatment.