All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars
 perplexus dot info

 The Unknown Side (Posted on 2002-07-01)
ABC is a triangle:
• Angle A < 90.
• D is a point on BC such that BD = DC.
• M is a point on BC such that AM is perpendicular to BC.

If
• BC = 12 and
• MC = 11
find the length of AC.
•  See The Solution Submitted by Dulanjana Rating: 2.9091 (11 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
 Trouble with the solution | Comment 11 of 15 |

If ABC is a right triangle, the hypotnuse must always be larger then the length of either legs.  SO for ABC:

BC>AC....

But BC=12 and the solution for AC is 14?  This can't be true for a real triangle.

Another approach to the problem yields a different answer.

Triangles ABC and MAC are similar because:

angle BAC= angle AMC= 90

Angle BCA= Angle ACM

Therefore:  (AC/CM)=(BC/AC) or AC^2=BC*CM

BC=12 and CM =11 so AC^2= 12*11=132

AC=sqrt132 =(approx) 11.5

Now, why don't both answers agree??????

 Posted by B on 2004-12-03 17:10:04

 Search: Search body:
Forums (0)