Flashcard Circumference vs Area- Circles

Front

What is the formula for the circumference of a circle?

Back

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

Front

What does the term 'circumference' refer to?

Back

The distance around a circle.

Front

If the diameter of a circle is 10 cm, what is the circumference?

Back

31.4 cm (C = πd = π * 10).

Front

What is the relationship between diameter and radius?

Back

The radius is half of the diameter (r = d/2).

Front

What is the value of π (pi) approximately?

Back

3.14.

Front

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

Back

31.4 cm (C = 2πr = 2 * π * 5).

Front

What is the area of a circle formula?

Back

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

Front

How do you find the diameter if you know the circumference?

Back

d = C/π.

Front

What is the area of a circle with a radius of 3 cm?

Back

28.26 cm² (A = π * 3²).

Front

What is the difference between circumference and area?

Back

Circumference measures the distance around a circle, while area measures the space inside the circle.