Circumference

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula: C = 2πr, where r is the radius.

Front

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

Back

C = 2π(5) = 10π cm.

Front

What is the relationship between diameter and radius?

Back

The diameter (d) of a circle is twice the radius: d = 2r.

Front

If the diameter of a circle is 10 inches, what is the radius?

Back

The radius is 5 inches, since r = d/2.

Front

What is the value of π (Pi) approximately?

Back

π is approximately 3.14.

Front

How do you convert radius to diameter?

Back

Multiply the radius by 2: d = 2r.

Front

How do you convert diameter to radius?

Back

Divide the diameter by 2: r = d/2.

Front

What is the circumference of a circle with a radius of 8 in terms of Pi?

Back

C = 16π.

Front

If the circumference of a circle is 31.4 cm, what is the radius?

Back

r = C/(2π) = 31.4/(2π) = 5 cm.

Front

What is the circumference of a circle with a diameter of 12 cm?

Back

C = πd = π(12) = 12π cm.