# MATH Geniuses -- I need your help!!!

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#### Bat-mite

##### Rocketeer in MD
To anyone who is a math whiz -- I need your help.

Please see the illustration. If I know the radius of a circle, and I know the length of the secant AB, and that's all I know, how do I calculate X (the red segment, i.e., the distance from the secant to the circumference)?

I'm not looking for a math lesson, just a simple equation I can use to measure that distance. Thanks!

#### blackbrandt

##### That Darn College Student
I don't see a pic.

However, if the problem I'm thinking of is the same, you use a triangle to solve it. Post a pic and I'll post a solution. #CalcIIperks

#### Bat-mite

##### Rocketeer in MD
I don't see a pic.

However, if the problem I'm thinking of is the same, you use a triangle to solve it. Post a pic and I'll post a solution. #CalcIIperks
Woops, I forgot the pic. BUT ... in the mean time, I asked someone in the office and we worked it out. And yes, using a triangle.

As it turns out, it's: