Circle Review 1

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 the relationship between the radius and diameter of a circle?

Back

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

Front

How do you find the measure of an angle formed by two chords in a circle?

Back

The measure of the angle is equal to half the sum of the measures of the arcs intercepted by the angle.

Front

What is the definition of 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 at the point of contact?

Back

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

Front

How do you calculate the length of an arc in a circle?

Back

Arc length = (θ/360) × 2πr, where θ is the central angle in degrees.

Front

What is the formula for the area of a sector of a circle?

Back

Area of sector = (θ/360) × πr², where θ is the central angle in degrees.

Front

What is the definition of a chord in a circle?

Back

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