I am a graduate student of Mathematics.Although I am doing good in my Masters' courses,I have to admit that I am a bit weak in basic Mathematics specially in elementary geometry.So,in this summer vacation I am planning to brush up those topics and fix my weakness.But,unfortunately,I have not found any reference that covers all the topics in geometry e.g. lines,angles,triangles,circles,tangents,quadrilaterals,rectangles,parallelograms.I am looking for a book that I can follow as textbook.Can someone suggest me a reference?
Addendum
I have tried Euclid's elements but it is not very helpful.So,please suggest a book that is good for beginners.
I can think on several options, one of them is Elementary Geometry from an advanced standpoint by E.Moise. But if you are looking for exercises like in math olympiads, there is a lot of material like in https://artofproblemsolving.com/community
I would suggest reading this other answer also.