Definition
A right-triangle diagram used in AC electrical theory to show the relationship between resistance, reactance, and impedance in a circuit. Resistance is drawn along the horizontal side, reactance along the vertical side, and impedance forms the hypotenuse. The total impedance of the circuit equals the square root of the sum of the squares of the resistance and reactance, the same relationship as the sides of a right triangle.
Plain English
A simple triangle drawing that helps you work out the total opposition to current flow in an AC circuit. Two known values (resistance and reactance) form the short sides, and the answer (impedance) is the long slanted side.
Context Anchor
Seen in aircraft electrical theory, avionics training, and maintenance troubleshooting for alternating-current circuits.
Derivation
Impedance comes from the Latin impedire, meaning 'to hinder' or 'get in the way of.' In an AC circuit, impedance is whatever hinders current flow. Calling the diagram a triangle reflects the fact that the three quantities relate to each other exactly like the three sides of a right triangle.
Why Pilots Care
Allows accurate diagnosis of electrical issues that affect instrument reliability and radio performance.
Analogy
Think of it like walking against both a steady slope and a side wind. Each one slows you in a different way, and the total effort is the combined result. The impedance triangle is a way to picture that combined electrical effect.
Intuition Check
Do not read “impedance triangle” as a physical triangular aircraft part. It is a drawing used to show an electrical relationship.
Example Sentence 1
The instructor drew an impedance triangle on the board to show how resistance and reactance combine to produce total impedance.
Example Sentence 2
By applying the impedance triangle the mechanic quickly identified why the navigation radios were receiving interference.