perplexus.info :: Geometry : Measure that angle III

Home > Shapes > Geometry

Measure that angle III (Posted on 2004-09-07)

Triangle ABC has side AB=AC, and angle BAC = 20 degrees.

D is a point on side AC with AD=BC. Find angle DBC.

Solve this without trigonometry.

See The Solution Submitted by Brian Smith

Rating: 3.2000 (5 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

re(3): Solution by cheating

| Comment 14 of 25 |

(In reply to re(2): Solution by cheating by Ken Haley)

Exactly, I didn't prove that... that's where I cheated. If you look at a problem called "Measure That Angle" (no II or III) you'll see that for a 20 degree isosceles triangle, you will have AD = DE = EB = BC.

I didn't prove it, I cheated and used prior knowledge.

Posted by nikki on 2004-09-09 08:26:03

Please log in:

Login:
Password:
Remember me:

Sign up! \| Forgot password

Search:

Search body:

Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (3)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info