(OL) Circles and Tangent Lines

Front

What is a circle?

Back

A circle is a set of points in a plane that are equidistant from a fixed point called the center.

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the diameter of a circle?

Back

The diameter is twice the length of the radius and is the longest distance across the circle, passing through the center.

Front

What is a tangent line?

Back

A tangent line is a straight line that touches a circle at exactly one point, called the point of tangency.

Front

How do you find the circumference of a circle?

Back

The circumference can be found using the formula C = 2πr, where r is the radius.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius (d = 2r).

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is the difference between a secant and a tangent?

Back

A secant intersects the circle at two points, while a tangent touches the circle at only one point.

Front

What is the area of a circle?

Back

The area can be calculated using the formula A = πr², where r is the radius.

Front

What is the formula for the perimeter of a circle?

Back

The perimeter (circumference) is given by C = πd, where d is the diameter.