A regular pentagon has the following dimensions:

AB=BC=CD=DE=AE=BG=EG=1 | Height AH=EK=\(\frac12\cos 18 = \frac12\sqrt{5+2\sqrt5}\) |

AC=AD=BD=BE=CE=Φ | Circumcenter AJ=\(\frac{\sqrt{50+10\sqrt5}}{10}\)=BJ=CJ=DJ=EJ |

BF=EF=Φ/2 | Inradius JK=\(\frac{\sqrt{25+10\sqrt5}}{10}\)=HJ |

CG=DG=Φ-1=1/Φ | FH=\(\cos18 = \sqrt{\frac{5+\sqrt5}{8}}\) |

AF=FG=cos 54= \(\sqrt{\frac{5-\sqrt5}{8}}\) | FJ=JK/Φ |

AG=\(2\cos 54 = \sqrt{\frac{5-\sqrt5}{2}}\) | GJ=AJ/Φ |

CH=DH=BK=CK=1/2 | GH=AF/Φ=\(\frac12\sqrt{5-2\sqrt5}\) |