Topic explanation

Standard explanation

A diameter has distance 0 from O and is longest. As the foot M moves toward the rim, the chord shrinks. Pythagoras: half-chord = sqrt(r^2 - d^2).

Key points

• diameter longest
• equal chords <=> equal distance
• LONGEST CHORD: A diameter has distance 0 from O and is longest. As the foot M moves toward the rim, the chord shrinks. Pythagoras: half
• keep the ideas separate
• Longest Chord: A diameter has distance 0 from O and is longest. As the foot M moves toward the rim, the chord shrin
• WHAT — LONGEST CHORD: A diameter has distance 0 from O and is longest. As the foot M moves toward the rim, the chord shrin
• HOW — Use the idea: Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check
• CORE UNDERSTANDING: A diameter has distance 0 from O and is longest. As the foot M moves toward the rim, the chord shrin

Labelled diagram