Coaching Centre
Circle terms and chord properties
Naming parts of a circle, the perpendicular from the centre bisects a chord, and equal chords are equidistant from the centre.
Terms
Chord theorems
A chord of length $16$ cm is in a circle of radius $10$ cm. How far is it from the centre?
Chord $16$, radius $10$. Distance from the centre?
$\sqrt{100 - 64}$.
Radius $13$, chord is $5$ from the centre. Chord length?
Half-chord $12$.
A chord of length $8$ is $3$ from the centre. Radius?
$\sqrt{16 + 9}$.
A line touching a circle at exactly one point is a:
Definition.
The longest possible chord is:
It passes through the centre.
Two equal chords; one is $7$ cm from the centre. Distance of the other?
Equal chords are equidistant.
Radius $17$, chord $15$ from the centre. Chord length?
Half-chord $\sqrt{289 - 225} = 8$.
A line from the centre bisects a chord. It meets the chord at:
Converse of the chord theorem.
New numbers every time. Keep going until you get five in a row.