Circles Unit Review

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

Circumference = 2πr, where r is the radius.

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

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 length of an arc in a circle?

Back

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

Front

What is a chord in a circle?

Back

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

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 central angle of a circle?

Back

A central angle is an angle whose vertex is at the center of the circle and whose sides are radii.

Front

What is the relationship between the radius and the area of a circle?

Back

The area of a circle increases with the square of the radius.

Front

What is the formula to find the coordinates of the center of a circle given its equation?

Back

For the equation (x - h)² + (y - k)² = r², the center is (h, k).