Theese are NOT viking runes. They are an older Rune alphabet, from around year 500 and earlier. They are called the elder futhark. The viking Rune alphabets have usually only 16 runes and there are several different alphabets from that time.
Pentagram symbol - representing the five elements of creation and it's attributes. Note : If you superimpose the vitruvian man figure over it, you see how it also represents the sacred geometry of body of man.