A circle is defined as a simple closed curve where all points are equidistant from a fixed point called the ___.

Centre

The distance between the centre of a circle and any point on the circumference is known as the ___.

Radius

The longest chord of a circle is called the ___.

Diameter

True or False: The radius of a circle is twice the length of the diameter.

False. The radius is half the diameter.

What is the difference between a minor arc and a major arc in a circle?

A minor arc is the shorter segment of the circle, while a major arc is the longer segment.

Fill in the blank: A ___ is a line segment whose endpoints lie on the circle.

Chord

Riddle: I am a part of a circle and named by three points, two are my endpoints, and one lies in between. What am I?

An arc

What is the relationship between diameter and radius in a circle?

The diameter is equal to 2 times the radius.

An arc that is longer than a semicircle is called a ___.

Major arc

True or False: A circle can be defined as a curve where points are at varying distances from the center.

False. All points in a circle are at the same distance from the center.

What is the formula for calculating the circumference of a circle?

The circumference of a circle is calculated using the formula C = 2πr, where r is the radius.

Fill in the blank: The diameter of a circle is equal to ___ times the radius.

2

True or False: The interior of a circle includes all points that are farther away from the center than the radius.

False. The interior of a circle includes all points that are closer to the center than the radius.

What distinguishes concentric circles from other circles?

Concentric circles have the same center but different radii.

Riddle: I am a closed curve where every point is equidistant from the center. What am I?

A circle.

When drawing a circle with a compass, what is the first step?

Fix a pointed pencil in the compass and place the metal tip at a point on a ruler to measure the radius.

The point 'O' in circle geometry typically represents what?

The center of the circle.

Fill in the blank: Circles with the same center but different radii are called ___ circles.

Concentric

If the radius of a circle is 3 cm, what is the circumference?

The circumference is 6π cm.

Explain the relationship between the radius and the diameter of a circle.

The diameter is twice the length of the radius; it can be expressed as d = 2r.

The radius of a circle is 3.4 cm. What is the diameter?

Diameter = 2 × radius = 2 × 3.4 cm = 6.8 cm.

Circumference of a circle can be calculated using which formula?

Circumference = 2 × π × radius.

If the circumference of a circle is 44 cm, what is the radius?

Using the formula Circumference = 2 × π × radius, we can rearrange to find radius = Circumference / (2 × π). For a circumference of 44 cm, radius = 44 cm / (2 × 22/7) = 7 cm.

The diameter of a circle is 2.8 cm. What is the circumference?

Circumference = π × diameter = (22/7) × (2.8 cm) = 8.8 cm.