Circle Review

Front

What is a tangent in relation to a circle?

Back

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

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 formula for the circumference of a circle?

Back

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

Front

What is the diameter of a circle?

Back

The diameter is the distance across the circle through its center, equal to twice the radius.

Front

What is a radius in a circle?

Back

A radius is a line segment from the center of the circle to any point on its circumference.

Front

How do you find the circumference of a circle if the radius is 14 inches?

Back

C = 2π(14) = 28π ≈ 87.92 inches.

Front

What is a sector of a circle?

Back

A sector is a portion of a circle enclosed by two radii and the arc between them.

Front

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

Back

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

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 formula for the area of a sector?

Back

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