Pyramid problem: plane EFCD is orthogonal to the pyramid side SAB

[skyler1251]

In a square pyramid,plane EFCD is orthogonal to the pyramid side SAB ,prove that EF is parallel to AB.
File with drawing attached,thanks in advance.

 

[Deleted member 4993]

In a square pyramid,plane EFCD is orthogonal to the pyramid side SAB ,prove that EF is parallel to AB.
File with drawing attached,thanks in advance.
View attachment 3047

Please share your work with us.

You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

http://www.freemathhelp.com/forum/th...217#post322217

We can help - we only help after you have shown your work - or ask a specific question (e.g. "are these correct?")