Online Course Discussion Forum

返回至:站点

Problem 8.15

 
 
MurenJimmy的头像
Problem 8.15
MurenJimmy - 2017年11月1日 Wednesday 21:10
 

Suppose a trapezoid ABCD with base AD is inscribed in a circle. If AB=4, then what is CD?

I made the trapezoid, and I remember that if we draw diagonals AC and BD and call the intersection O, then triangles AOB and COD have the same area, but I don't know how to go on from there, or maybe I am using the wrong strategy?

 
LensmireJohn的头像
Re: Problem 8.15
LensmireJohn - 2017年11月3日 Friday 15:18
 

Often a good thing to think about when you are stuck is the information the problem gives you. We know basically:

  1. We have a trapezoid $ABCD$ with base $AD$.
  2. $AB=4$.
  3. The trapezoid is inscribed in a circle, that is, $ABCD$ is a cyclic quadrilateral.

Keeping in mind all of this information should help get you started!

Let us know if you have more questions.

 
显示父帖