Circle terms

Front

What is the definition of a radius (r) in a circle?

Back

The radius (r) is the distance from the center of the circle to any point on its circumference.

Front

What is the definition of a diameter (d) in a circle?

Back

The diameter (d) is the distance across the circle through its center, equal to twice the radius (d = 2r).

Front

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

Back

The diameter is 20 ft, calculated as d = 2r = 2 * 10 ft.

Front

If the diameter of a circle is 14 m, what is the radius?

Back

The radius is 7 m, calculated as r = d/2 = 14 m / 2.

Front

What is the formula to calculate the circumference (C) of a circle?

Back

The circumference is calculated using the formula C = πd or C = 2πr.

Front

What is the area (A) of a circle with radius r?

Back

The area is calculated using the formula A = πr^2.

Front

What is the relationship between radius and diameter?

Back

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

Front

What does π (pi) represent in circle geometry?

Back

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

Front

If a circle has a circumference of 31.4 m, what is its diameter?

Back

The diameter is 10 m, calculated as d = C/π = 31.4 m / π.

Front

What is the center of a circle?

Back

The center is the point that is equidistant from all points on the circumference of the circle.