Thread: Euclidean Geometry

1. Euclidean Geometry

if AB < CD, prove that 2AB < 2CD

2. Re: Euclidean Geometry

First, AB is the length of the segment from A to B so these are numbers. To prove that "if AB< CD then 2AB< 2CD" show that, from AB< CD, it follows that CD- AB> 0. Then use the fact that the product of two positive numbers is positive.