The Converse Of A Theorem
Remember the previous page when we learnt about the ⇐ symbol? This means the 'converse'. Let's use the Pythagoras'
theorem as an example. We know that if an angle is 90°, we can use the formula AB2 = BC2
+ CA2. In terms of using the arrows, we could write it as Angle = 90° ⇒ AB2 = BC2
+ CA2. The converse of this is that if we use the formula AB2 = BC2
+ CA2, the angle has to be 90°. In arrows, that would be Angle = 90° ⇐ AB2 = BC2
+ CA2 (meaning the converse is true).