Parts of a Circle

Front

What is a radius?

Back

A radius is a line segment that connects the center of a circle to any point on its circumference.

Front

What is a diameter?

Back

A diameter is a line segment that passes through the center of a circle and connects two points on its circumference. It is twice the length of the radius.

Tags

CCSS.HSG.C.A.2

Front

What is the circumference of a circle?

Back

The circumference is the distance around the outside of a circle.

Front

How do you calculate the circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Tags

CCSS.7.G.B.4

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.

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circumference of the circle.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Tags

CCSS.7.G.B.4

Front

What is a semicircle?

Back

A semicircle is half of a circle, formed by cutting a whole circle along a diameter.

Front

What is a sector of a circle?

Back

A sector is a portion of a circle enclosed by two radii and the arc between them.