Lesson Plan: Parallel Chords and Tangents in a Circle Mathematics
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to use the parallel chords and the parallel tangents and chords of a circle to deduce the equal measures of the arcs between them and find missing lengths or angles.
Objectives
Students will be able to
- understand that the measures of the arcs between parallel chords of a circle are equal,
- understand that the measures of the arcs between a chord and a parallel tangent of a circle are equal,
- understand that if the measures of the arcs between two chords (or between a chord and a tangent) are equal, we can deduce that the lines must be parallel,
- use theories of parallel chords and parallel chords and tangents to find unknown angles and lengths.
Prerequisites
Students should already be familiar with
- chords and tangents of a circle,
- the Pythagorean theorem,
- the central angle theorem and arc measures,
- the relationship between equal arcs and chords.
Exclusions
Students will not cover
- the equation of a line (in any form),
- the equation of a circle.
