# Theorems

## First some revision on Angles and Triangles

For proofs of Junior Cert geometry theorems or Leaving Cert theorems click theorems

## Geometry Theorems

The idea of a formal proof is a very important one in mathematics. A statement is proposed, and is then proved by a sequence of statements, each of which can be independently verifiable, leading to the inescapable conclusion that the theorem is indeed valid. There is no room for argument. Unlike English, for example, there is no possibility of a personal viewpoint.

Among the most important proofs in traditional mathematics are the proofs of the theorems from Euclidean geometry. Although there are thousands of proofs, on our course we just have to learn ten.

Also examined in this question are enlargements, which are a practical application of the particular theorems on our course. In effect, we use a couple of these theorems to find lengths and areas of images under the type of transformation known as an enlargement.

http://www.mathsisfun.com/geometry/circle-theorems.html

Junior Cert Maths – Geometry Theorems

A concise description of what you need to know to answer exam questions based on the geometry theorems on the Junior Cert course.