# Circles

A circle is a closed curved line whose points are all the same distance from a fixed point called the center.

#### Center Circle

The center is the point which is equidistant from all points in the circle.

#### Radius of the Circle

The radius is the distance from the center to the edge of the circle.

#### Chord

A chord is a line segment that joins two points in the circle.

#### Diameter

The diameter is a chord that passes through the center of the circle.

#### Arc

An arc is each of the segments of the circumference that a chord divides. It is usually associated with the lower arc.

#### Semicircle

A semicircle is each of the two equal parts in which a diameter divides a circle.

### Area of a Circle

#### Examples

The surface of a table consists of a square of 1 m per side and two semicircles attached at opposite ends. Calculate the area of the table.

Calculate the shaded area of the figure below if the radius of the larger circle is 6 cm and the radius of the smaller circles are 2 cm.

In a circular park with a radius of 250 m there are 7 lamps whose bases are circles with a radius of 1 m. The entire area of the park has grass with the exception of the bases for the lamps. Calculate the total lawn area.

A chord of 48 cm is 7 cm from the center of a circle. Calculate the area of the circle.

Calculate the shaded area, knowing that the side of the outer square is 6 cm and the radius of the circle is 3 cm.