Question

What do I need to know about all circle such as radius, diameter, chord, arc, circumference, circular sector, semicircle, concentric circles, congruent circles, point of tangency, tangent & tangent circles? What are these learning objectives? What is the width and length for these circles name above? Is there any examples for these circles name above?

Answer 1

The circle is a closed curve equidistance from a point called the center of the circle

The distance from the center to any point on the closed curve is called the radius

Any distance joining 2 points on the closed curve and passes through the center of the circle is called a diameter of the circle

The closed curve is called the circumference of the circle, which means the length of the circle

The circumference of the circle is equal to the product of the diameter and the constant value pi

`C=\pi* d`

C is the circumference, d is the diameter

The diameter of the circle is twice its radius, then

`d=2r`

So we can write the rule of the circumference as

`C=2*\pi* r`

Any line segment joining 2 points on the circumference and does not pass through the center is called a chord of the circle

The sector is a part of the circle formed from two radii and an arc

Now, congruent circles mean circles have the same diameter, radii, circumference, area, and everything are equal in them

Concentric circles are the circles that have the same center with different radii

Let me show you

The tangent of a circle is a line that touches the circle in only ONE point

It is perpendicular to the radius or the diameter at the point of touching which is called the point of tangency

The measure of the circle is 360 degrees