Geometry 11.1 Find Circumference and Arc Length

Front

What is the formula for the circumference of a circle?

Back

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

Front

If the diameter of a circle is 14 cm, what is the circumference?

Back

43.98 cm (C = πd = π * 14).

Front

What is the distance around a circle called?

Back

Circumference.

Front

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

Back

31.4 in (C = 2πr = 2π * 5).

Front

What is an arc in a circle?

Back

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

Front

How do you find the length of an arc?

Back

Arc length = (θ/360) * C, 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 circumference of 31.4 cm, what is its radius?

Back

5 cm (C = 2πr, so r = C/(2π)).

Front

What is the formula for the area of a circle?

Back

A = πr².

Front

If the circumference of a circle is 28 cm, what is the diameter?

Back

Diameter = 28/π ≈ 8.86 cm.