Area and Circumference

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is given by the formula: C = 2πr, where r is the radius.

Front

What is the relationship between diameter and radius?

Back

The diameter (d) of a circle is twice the radius (r): d = 2r.

Front

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

Back

The diameter is 10 cm.

Front

What is the formula for the area of a circle?

Back

The area (A) of a circle is given by the formula: A = πr², where r is the radius.

Front

If the radius of a circle is 3 ft, what is the area?

Back

The area is 28.27 ft² (using A = π(3)²).

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.

Front

How do you calculate the circumference if the diameter is known?

Back

Use the formula: C = πd, where d is the diameter.

Front

What is the circumference of a circle with a diameter of 8 cm?

Back

The circumference is 25.13 cm (using C = π(8)).

Front

What is the diameter of a circle with a circumference of 31.4 cm?

Back

The diameter is 10 cm (using d = C/π).

Front

If a circle has a radius of 4 m, what is its circumference?

Back

The circumference is 25.13 m (using C = 2π(4)).