Circles
Parts of a circle
You will need to make sure you can identify all aspects of a circle.
Let’s start with some key lines that make elements of a circle.
The radius is always half the diameter.
The diameter goes across the circle, through the middle of the circle.
A chord it is a line that touches the circumference at two points but does not cross the middle of the circle.
A __tangent __ to the circle touches the circle at only one point.
The __circumference __of the circle (it’s like the perimeter of the circle).
A secant is a line that intersects the circle in two different points.
An arc this is part of the circumference.
A sector it is part of the circle enclosed by two radius or by two points on the circumference.
An area not enclosed by two radii is called a segment.
- What is the name for the area of a circle between the circumference and two radii?
- Sector
- What is half the diameter?
- Radius
- What touches a circle at one point?
- Tangent