Bell Work Circles: Circumference and Area

Front

What is the formula used to find the circumference of a circle?

Back

C = πd or C = 2πr

Front

What is the formula to find the area of a circle?

Back

A = πr²

Front

What is the relationship between radius and diameter?

Back

Diameter is twice the radius (d = 2r).

Front

What is the value of π (pi) approximately?

Back

π ≈ 3.14

Front

If the radius of a circle is 7 cm, what is the circumference?

Back

C = 2πr = 2 × π × 7 ≈ 43.96 cm

Front

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

Back

A = πr² = π × 5² ≈ 78.54 cm²

Front

What is a radius in a circle?

Back

A radius is a line segment from the center of the circle to any point on its circumference.

Front

What is a diameter in a circle?

Back

A diameter is a line segment that passes through the center of the circle and has endpoints on the circumference.

Front

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

Back

Radius = Diameter / 2.

Front

What is the area of a circle with a radius of 10 cm?

Back

A = πr² = π × 10² ≈ 314.16 cm²