Circles Definitions

What is the definition of a circle?

• A circle is a three-dimensional shape with six faces.

• A circle is a polygon with four sides.

• A circle is a straight line with no endpoints.

• A circle is a closed curve in which all points are equidistant from the center point.

What is the radius of a circle?

• A line segment connecting the center of the circle to any point on its circumference.

• The distance between two points on the circumference of the circle.

• The area enclosed by the circle.

• The length of the circle's diameter.

What is the diameter of a circle?

• The diameter of a circle is the distance between any two points on the circumference.

• The diameter of a circle is the radius multiplied by 2.

• The diameter of a circle is a straight line that passes through the center of the circle and connects two points on the circumference.

• The diameter of a circle is the length of the curved line that forms the circumference.

What is the circumference of a circle?

• 2πd

• πr^2

• πr

• 2πr or πd

True or False: A circle is a closed curve.

• True or False: A circle is a straight line.

• True

• False

• True or False: A circle is an open curve.

True or False: The radius of a circle is half of its diameter.

• True

• The radius of a circle is one-third of its diameter

• The radius of a circle is equal to its diameter

• False

True or False: The circumference of a circle is equal to the sum of its radius and diameter.

• The circumference of a circle is equal to its radius

• True

• The circumference of a circle is equal to its diameter

• False

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

• pi * radius

• 2 * pi * radius

• 2 * radius

• pi * diameter

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

• A = πr^2

• A = r^2

• A = πd

• A = 2πr

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

• 8 cm

• 12 cm

• 15 cm

• 10 cm