Circle theorems are properties that are true for all circles, regardless of their size. There are six theorems to learn and recognise. Questions can have a combination of theorems. It is important to ...

Take any quadrilateral such as ABCD above. Construct the midpoints of each side and join them to form another quadrilateral EFGH. Varignon's Theorem asserts that the ...

It’s no wonder that farmers with fields in the plains surrounding Stonehenge, in southern England, face late-summer mornings with dread. On any given day at the height of the growing season, as many ...

Summary We state and prove a surprising incidence theorem that was discovered with the help of a computer graphics program. The theorem involves sixteen points on ten lines and five circles; our proof ...