(sometimes known as a pentalpha or pentangle or a star pentagon) is the shape of a five-pointed star drawn with five straight strokes.
The word pentagram comes from the Greek word πεντάγραμμον (pentagrammon), from πέντε (pente), "five" + γραμμή (grammē), "line".
The word "pentacle" is sometimes used synonymously with "pentagram".
The word pentalpha is a learned modern (17th-century) revival of a post-classical Greek name of the shape.(wikipedia)
A regular pentagram