Circles

Front

What is the circumference of a circle?

Back

The circumference is the distance around the circle, calculated as C = 2πr or C = πd, where r is the radius and d is the diameter.

Front

What is the area of a circle?

Back

The area is the space contained within the circle, calculated as A = πr², where r is the radius.

Front

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

Back

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

Front

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

Back

A = πr², where r is the radius.

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 connects two points on its circumference. It is twice the length of the radius.

Front

If the radius of a circle is 7 inches, what is the area?

Back

A = π(7)² ≈ 153.94 in².

Front

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

Back

C = π(10) ≈ 31.42 inches.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius (d = 2r).

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.