I’m not sure but i thinks it’s 1
Mass of a triangles : 1
Because you’re trying to balance the diagram and if you noticed in line A there’s 2 triangles , 3 circles , and 6 squares .
On line B there’s 2 circles , 3 squares , and 5 triangles , so in order to balance it there should be another triangle in it so it can be 6 triangles .
