8.2: Properties of a Chord Circle Geometry
What is a chord? a chord is line segment joining two endpoints that lie on a circle.
What is a chord? A circle can have many chords but there is one special chord left to mention
What is a chord? It turns out that a diameter of a circle is the longest chord of this circle since it passes through the center. A diameter satisfies the definition of a chord, however, a chord is not necessarily a diameter. Therefore, every diameter is a chord, but not every chord is a diameter.
Working with Chords, Radii and Diameters
Chord Property #1, #2 and #3 A perpendicular line from the centre of a chord to the centre of a circle: #1: Makes a 90° angle with the chord #2: Creates two equal line segments RS and QR #3: Must pass through the centre of the circle O
Chord Property #1, #2 and #3 Let’s play with this…. /chordBisector.htm /chordBisector.htm le/chord-perpendicular-bisector.html le/chord-perpendicular-bisector.html
Let’s get crazy… b Find b.
Let’s get crazy… b Step 1: What do we need to find? We need a radius to complete this big triangle. Find b.
Let’s get crazy… b Find b. How do we find a radius? We can draw multiple radii (radiuses).
Let’s get crazy… b Find b. How do we find a radius? Now what do we have and what will we do?
Let’s get crazy… b Find b. How do we find a radius? We create this triangle but how do we get the missing side?
Let’s get crazy… b Find b. How do we find a radius? We create this triangle but how do we get the missing side? 4
Let’s get crazy… b Find b. !!!Pythagorean Theorem!!! a 2 +b 2 =c 2 so =169 so b is
Assignment Time Pg , 4, 5, 6, 7, 10, 11, 18, 19(Draw it out!)