Circumference, Area, Arcs and Sectors Review

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where C is the circumference and r is the radius.

Front

How do you calculate the area of a circle?

Back

A = πr², where A is the area and r is the radius.

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

How do you find the area of a sector?

Back

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

Front

What is an arc in a circle?

Back

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

Front

How do you calculate the length of an arc?

Back

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

Front

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

Back

Diameter = 2 × radius.

Front

If a circle has a radius of 10 cm, what is its circumference?

Back

C = 2π(10) = 62.83 cm.

Front

If a circle has a radius of 5 cm, what is its area?

Back

A = π(5)² = 78.54 cm².

Front

What is the area of a sector with a radius of 6 inches and a central angle of 60°?

Back

Area = (60/360) × π(6)² = 11.78 in².