Area and Circumference of a Circle

Front

What is the definition of a radius in a circle?

Back

The radius is the measurement from the center of a circle to an edge of the circle.

Front

What is the definition of a diameter in a circle?

Back

The diameter is the measurement from one edge of the circle to the opposite edge, passing through the center.

Front

How do you calculate the circumference of a circle?

Back

Circumference = π × diameter.

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

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

Back

Diameter = 2 × radius = 10 cm.

Front

If the diameter of a circle is 10 cm, what is the circumference using π = 3.14?

Back

Circumference = π × diameter = 3.14 × 10 = 31.4 cm.

Front

What is the approximate value of π?

Back

π is approximately 3.14.

Front

If the radius of a circle is doubled, how does the area change?

Back

The area increases by a factor of four.

Front

What is the circumference of a circle with a diameter of 24 inches?

Back

Circumference = π × diameter = 3.14 × 24 = 75.36 inches.

Front

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

Back

Area = π × radius² = 3.14 × 3² = 28.26 cm².