1. From chapter 10, I have learned that the diameter of a circle is only the radius doubled. A central angle has a vertex at the center point of a circle and contains two radi. An arc is the section of a circle in between two points. The arc is equal to the angle in between the two points. A tangent line is a line that intercepts a circle at exactly one point. That point is called the point of tangency. The line is perpendicular to a radius drawn to the point of tangency.

2. One career that would need to use the information we've learned from chapter 10 would be astronomy. Why? Because during an eclipse they need to understand exactly what is occuring when the light bounces from one object to another.

3. Why dont the rules from quadrilateral angles apply to circles too?