Calculating how long a tangent line is from a point outside of a circle can be tricky. It mostly has to do with understanding some shapes and their parts.

1. Getting to Know the Circle: First, you should know how the radius, the outside point, and the tangent line fit together.

2. Using the Correct Formula: You can find the length of the tangent (we'll call it $L$) using this formula:

   $L = \sqrt{d^2 - r^2}$

   Here, $d$ is the distance from the outside point to the center of the circle, and $r$ is the circle's radius.

3. Seeing It Clearly: It really helps to draw a picture. This will make it easier to see how the tangent line, the radius, and the distance all connect.

Even though it might seem tough at first, with some practice and the right steps, you can find out the lengths of the tangents.