Find triangles in an image

Given an image containing multiple shapes, design an algorithm to identify and label the triangles. Assume the image is given in binary format, where pixel value 0 represents the background and 1 represents the shapes. Describe the implementation of the algorithm and discuss its time complexity. Additional features include identifying the triangle angle types (acute, right, obtuse). Example Input [[0, 1, 0], [1, 1, 1], [0, 1, 0]]