Circumference and Area

Front

What is the formula for the area of a circle?

Back

The area (A) of a circle is calculated using the formula A = πr², where r is the radius of the circle.

Front

How do you calculate the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula C = 2πr, where r is the radius of the circle.

Front

What is the relationship between diameter and radius in a circle?

Back

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

Front

If the diameter of a circle is 10 cm, what is its radius?

Back

The radius of a circle with a diameter of 10 cm is 5 cm.

Front

What is the area of a circle with a radius of 7 cm?

Back

The area of a circle with a radius of 7 cm is approximately 153.94 cm² (using A = πr²).

Front

What is the circumference of a circle with a radius of 10 m?

Back

The circumference of a circle with a radius of 10 m is approximately 62.83 m (using C = 2πr).

Front

How do you convert diameter to radius?

Back

To convert diameter to radius, divide the diameter by 2.

Front

What is the area of a circle with a diameter of 14 cm?

Back

The area of a circle with a diameter of 14 cm is approximately 153.94 cm² (using A = πr², where r = 7 cm).

Front

What is the circumference of a circle with a diameter of 20 cm?

Back

The circumference of a circle with a diameter of 20 cm is approximately 62.83 cm (using C = πd).

Front

What is π (pi) and why is it important in circle calculations?

Back

π (pi) is a mathematical constant approximately equal to 3.14159. It is important in circle calculations as it relates the circumference and diameter of a circle.