Circumference and Area Applications

What is the formula to calculate the circumference of a circle using the radius?

• C = 2r

• C = r²

• C = 2πr

• C = πd

What does the term 'circumference' refer to in geometry?

• The area inside a circle

• The diameter of a circle

• The distance around the edge of a circle

• The height of a circle

Which of the following is NOT a way to calculate circumference?

• C = 2r

• C = r²

• C = πd

• C = 2πr

If you know the circumference of a round cake is 31.4 inches, what is the radius?

• 20 inches

• 15 inches

• 10 inches

• 5 inches

• 25.12 inches

• 12.56 inches

• 50.24 inches

• 31.4 inches

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

• 31.4 inches

• 25 inches

• 15.7 inches

• 10 inches

What is the radius if the circumference of a circle is approximately 18.84 inches?

• 12 inches

• 6 inches

• 3 inches

• 9 inches

If a circle has a diameter of 10 inches, what is its circumference?

• 25 inches

• 15.7 inches

• 20 inches

• 31.4 inches

Why is understanding circumference important in real life?

• It helps in measuring the area of squares.

• It only applies to theoretical math.

• It is used in cooking and construction.

• It has no practical applications.

What is the area of the circle? (Best Choice)

• 3π or about 9.42 in²

• 6π or about 18.84 in²

• 12π or about 37.68 in²

• 36π or about 113.04 in²