Math
Secants and chords.
Definition
A chord is a line segment with both endpoints on a circle. A secant is a line that intersects a circle at exactly two points, extending beyond the circle. Theorems about secants and chords relate the lengths of segments and the measures of intercepted arcs.
Examples
Real-world.
- 1 A diameter is the longest chord of a circle
- 2 Two secants drawn from the same external point: the products of their segments are equal
- 3 A chord 6 cm from the center of a circle with radius 10 cm has length 16 cm
Key Fact
Two chords intersecting inside a circle: (segment 1a)(segment 1b) = (segment 2a)(segment 2b)