Equilateral Angles
Part of the Angles section of Coddy's Geometry journey. Lesson 50 of 62.
An equilateral triangle has three equal sides, marked with matching ticks. It is isosceles three times over: every pair of sides is equal, so every pair of angles is equal, and three corners of x° obey 3x = 180. Every corner of every equilateral triangle measures exactly 60°.
Every equilateral triangle has three angles of 60°. Changing its side length changes its size, but not its angle measures.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Angles
1Meet the Angle
Your First AngleNaming AnglesAdding Adjacent AnglesDegrees and the Full TurnAcute, Right, ObtuseRecap: Adjacent Angles4Vertical Angles
Linear PairsVertical Angles Are EqualSolving with VerticalsAll Four AnglesRecap: At the Crossing7Crossing Parallel Lines
Parallel LinesCorresponding AnglesAlternate AnglesCo-interior AnglesWhich Rule Is ItRecap: The Three Pairs10Isosceles Triangles
Base Angles Are EqualFinding the ApexWhich Angles MatchEquilateral AnglesIsosceles at WorkRecap: Twin Corners2Straight Lines and Supplements
Angles on a LineSupplementary AnglesThree Angles on a LineWrite the EquationRecap: Along the Line5Around a Point
Angles Around a PointThe Missing AngleEqual SlicesFour Angles, One PointRecap: The Full Turn3Right Angles and Complements
Complementary AnglesFinding the ComplementPerpendicular LinesEqual Parts of a CornerRecap: The Right Corner6The Angle Bisector
The Angle BisectorBisected ExpressionsBisecting a Straight AngleRecap: Split in Half