# CIRCUMFERENCE AND CIRCLE

## Presentation on theme: "CIRCUMFERENCE AND CIRCLE"— Presentation transcript:

CIRCUMFERENCE AND CIRCLE

Circumference is a line whose points are equidistant to the center
Circle is a portion of plane or area in a circumference

THE CIRCUMFERENCE A circumference is a closed flat curved where all its points are equidistant from the fixed centre point The flat surface outlined by the circumference is called a circle Way at the bottom, change that like to „is called a circle“.

Elements of a circumference
Diameter. The straight line that goes through the center of the circumference and intersect it at two points Radius. It is the segment that connects the center of the circumference to any other point Secant. It is a straight line that intersects a circumference at two points Tangent. It is a straight line that crossed the circumference at only the point known as tangent point Arc. It is the fragment of the circumference between any two points Chord. It is the segment that connects any two points of the circumference Tangent Chord Radius Diameter Diameter: The straight line that goes through the CENTER of the ..... Radius. This is the segment..... CENTER Secant. This is..... Tangent. This is the straight line that crosses the ..... Arc. This is the ..... Chord. This is the..... Secant Arc

RADIUS The radius of a circle is the distance from the center of the circle to the outside edge. ESTHER CHANGE ALL THE „CENTRE“ words to „CENTER“

THE DIAMETER The diameter of a circle is the longest distance across a circle.  (The diameter cuts through the center of the circle.  This is what makes it the longest distance.)

PERIMETER OF A CIRCUMFERENCE
The perimeter is the distance around the outer edge. Circumference = where r = the radius of the circle and pi =

A chord of a circle A chord of a circle is a line segment that connects one point on the edge of the circle with another point on the circle. (The diameter is also a chord: it's just the longest possible chord of a circle) At the bottom: The diameter is also a chord. It is just the longest possible chord of a circle.

An arc of a circle is a segment of the circumference of the circle.

ANGLES

ANGLE Two rays that share the same endpoint form an angle.
The point where the rays intersect is called the vertex of the angle. The two rays are called the sides of the angle.

α We usually specify an angle using Greek letters like these α, β, γ
We can also specify an angle with the letters of its rects adding the symbol above them : rs r Esther, I think a, b, c is Arabic and not Greek. Isnt it? I dont know but thats what I always thought. α s

Measuring Angles ACUTE < 90º RIGHT= 90º OBTUSE > 90º FULL= 360º
We measure the size of an angle using degrees. ACUTE < 90º RIGHT= 90º OBTUSE > 90º FLAT = 180º FULL= 360º CLASIFICATION BY MEASUREMENT

PAIRS OF ANGLES b a a+b = 90º Complementary Angles:
Two angles are called complementary angles if the sum of their degree measurements are equals 90 degrees. b a a+b = 90º

ANGLE BISECTOR An angle bisector is a ray that divides an angle into two equal angles.

What kind of shape does have this pizza?

What would it be this portion of pizza in Geometry?