Circumference and Arc Length

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where C is circumference, d is diameter, and r is radius.

Front

If the diameter of a circle is 21 feet, what is the circumference?

Back

C = πd = π(21) ≈ 65.94 feet.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius: d = 2r.

Front

How do you calculate the arc length of a circle?

Back

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

Front

What is the circumference of a circle with a radius of 14 cm?

Back

C = 2π(14) ≈ 87.96 cm.

Front

What is an arc in a circle?

Back

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

Front

What is the difference between a minor arc and a major arc?

Back

A minor arc is less than 180 degrees, while a major arc is more than 180 degrees.

Front

If the circumference of a circle is 88 inches, what is the radius?

Back

r = C/(2π) = 88/(2π) ≈ 14 inches.

Front

What is the formula to find the area of a circle?

Back

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

Front

How do you convert the diameter of a circle to radius?

Back

Radius = Diameter/2.