October 29th, 2017, 07:34 AM |
#1 |

Newbie Joined: Oct 2017 From: France Posts: 2 Thanks: 0 | Can someone help?
Base of the pyramid quadrangle ABCDS is parallelogram ABCD. Also in the pyramid of ABCDS you can type sfere. Prove that the sum of the ABS and CDS wall areas are equal to the sum of the BCS and ADS wall areas. Can someone help me with that or give some nice hints? |

October 29th, 2017, 09:46 AM |
#2 |

Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 11,074 Thanks: 722 | |

October 29th, 2017, 10:05 AM |
#3 |

Newbie Joined: Oct 2017 From: France Posts: 2 Thanks: 0 |
Sphere* No, it doesn't help. This pyramid doesn't have to be regular... |