Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: 3-dimensional problem
Replies: 2   Last Post: Jun 20, 2006 7:45 PM

 Messages: [ Previous | Next ]
 NealAgMan@aol.com Posts: 181 Registered: 12/4/04
3-dimensional problem
Posted: Jun 17, 2006 11:54 AM

It's been a while, and I'm getting nowhere fast with this problem. Perhaps someone could lend me a hand, or at least point me in the right direction. This problem comes from the New York State Regents Exam in Solid Geometry, June, 1950, Part II, Question 22.

Triangle ABC has a right angle at C. Line segment AD is drawn perpendicular to plane ABC. Points E and F are the midpoints of line segments DC and DB respectively. Prove that line EF is perpendicular to the plane ADC.

Thanks in advance. Neal Silverman

Date Subject Author
6/17/06 NealAgMan@aol.com
6/20/06 talmanl@mscd.edu
6/20/06 talmanl@mscd.edu