What is the significance of the Pentangle? What do the 5 sides represent?

The poet pays particular attention to the Pentangle, the emblem of truth, known everywhere as "the endless knot." It is particularly suitable for Gawain because the five points of the star represent the five different ways in which Gawain, like purified gold, embodies faultless virtue. These five ways are in themselves five groups of five: 1) he is perfect in the five senses; 2) his five fingers are unfailing; 3) his faith is fixed firmly on the five wounds which Christ received on the cross; 4) he draws his strength from the five joys Mary had through Jesus; and 5) he embodies, better than any other living man, the five virtues. These virtues are Franchise, Fellowship, Cleanness, Courtesy, and above all, Charity.