Subject: Geometry

Chords And Arcs

Chord

A chord is a line that joins any two points in the circle. A chord that passes in the center of the circle is the diameter of a circle.


\bar{AB} , \bar{CD} , and \bar{EF} are the Chords in the cirlce; \bar{CD} is the diameter.

Arc

An arc, on the other hand is a connected part or section of the circumference of a circle.


The black portion of the circumference of the circle in the figure above is called an arc.

Measuring Chords and Arcs

In measuring chords and arcs in circles, we need to follow certain rules and guidelines so that our measurement would be as accurate as possible.

Guidelines in measuring chords and arcs

In measuring chords, there are at least four important guidelines to remember. These are the following:

  • The measure of the intercepted arc is equal to the measure of the central angle.
  • Half the measure of the intercepted arc is the same as the measure of the inscribed angle.
  • A line or a line segment that connects two points on a circle is called a chord.
  • A line passing through two points on a circle is called a secant.