Pythagoras gets everywhere in Maths. [br][br]The rules of the Right Angled Triangle will form the basis of a reasonable amount of work that you will do within the curriculum in terms of geometry.[br][br]a[sup]2 [/sup]+ b[sup]2 [/sup]= c[sup]2[br][br][size=100]Length a squared + Length b squared = Length c squared[/size][br][/sup]This applies only within Right Angled Triangles. You can disprove that a triangle has a right angle based on the above rule.