Review of Circles

Front

What is the definition of 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 formula for the circumference of a circle?

Back

C = 2πr, where r is the radius of the circle.

Front

What is the formula for the area of a circle?

Back

A = πr², where r is the radius of the circle.

Front

What is an arc in a circle?

Back

An arc is a portion of the circumference of a circle.

Front

How do you find the measure of an arc?

Back

The measure of an arc can be found using the formula: (central angle/360) * circumference.

Front

What is a tangent to a circle?

Back

A tangent is a line that touches the circle at exactly one point.

Front

What is the relationship between a radius and a tangent?

Back

A radius drawn to the point of tangency is perpendicular to the tangent line.

Front

What is the equation of a circle with center (h, k) and radius r?

Back

(x - h)² + (y - k)² = r².

Front

What does it mean for two lines to be parallel to a circle?

Back

Two lines are parallel to a circle if they do not intersect the circle at any point.

Front

What is the definition of a chord in a circle?

Back

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