Understanding Circles for Grade 10

Front

Circle

Back

A set of all points in a plane equidistant from a given point (center).

Front

Radius

Back

Distance from the center to any point on the circle.

Front

Diameter

Back

A chord passing through the center; 2 times radius.

Front

Circumference

Back

The perimeter of a circle; 2πr.

Front

Area of a Circle

Back

πr²

Front

Chord

Back

A line segment with both endpoints on the circle.

Front

Secant

Back

A line that intersects a circle at two points.

Front

Tangent

Back

A line that touches the circle at exactly one point.

Front

Arc

Back

A portion of the circumference of a circle.

Front

Sector

Back

A region bounded by two radii and an arc.