Circumference and Arc Length

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 length of an arc?

Back

Arc Length = (θ/360) × C, where θ is the central angle in degrees and C is the circumference.

Front

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

Back

Diameter = 2 × Radius.

Front

What is the value of π (pi) approximately?

Back

π ≈ 3.14.

Front

If the radius of a circle is 5 cm, what is its circumference?

Back

C = 2π(5) ≈ 31.4 cm.

Front

What is the central angle of a circle?

Back

The angle whose vertex is at the center of the circle and whose sides intersect the circle.

Front

How do you convert degrees to radians?

Back

Radians = Degrees × (π/180).

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

Front

If an arc subtends a central angle of 90 degrees, what fraction of the circle does it represent?

Back

1/4 of the circle.

Front

What is the formula for the length of an arc in radians?

Back

Arc Length = rθ, where r is the radius and θ is the angle in radians.