7.09 is not greater than 7.2 because .09 is on the hundren place while .2 is on the tenth place. If you wanted to know whether 7.09 is greater 7.2, you had to move one time on the right for 7.2 and it will give you 7.20 which is now in a hundren place.
So if you look closely 7.20 will be greater than 7.09
It is comparing two things without using like or as so it is a Metaphor
The purpose and effect of Beowulf describing his own great deeds rely on showing how confident he is about his strength and bravery to fight the monster. In this way, he is demonstrating his honor and fearless pursues to others.