-Initially, some of the headings were not formatted as headings, so emphasising the headers as strong was suitable
-Moreover, it was written that the diagonals of a rectangle is "mutually perpendicular", which is not true for a rectangle, so I removed it to avoid confusion
-Changed the mathematical equations through inserting "" and using LaTex Equation Editor to copy the image address of the equation into the round brackets
-Added more info about triangles by specifying the types of triangles
-Added info on a Trapezium as a 2D Polygon
