2 Chapter 1 Introduction to Statistical Quality Control, 5th Edition by Douglas C. Montgomery. 3Copyright (c) 2005 John Wiley & Sons, Inc.Chapter 1 Introduction to Statistical Quality Control, 5th Edition by Douglas C. Montgomery. 4Copyright (c) 2005 John Wiley & Sons, Inc. Learning Objectives.
Notice it always remains an equiangular triangle. The angles A,B and C always remain equal in measure. An equiangular triangle is a triangle where all three interior angles are equal in measure. Because the interior angles of any triangle always add up to 180Â°, each angle is always a third of that, or 60Â° The sides of an equiangular triangle are all the same length (congruent), and so an equiangular triangle is really the same thing as an equilateral triangle. See Equilateral Triangles. Properties
1 So, the angles of an equilateral triangle are Congruent Angles. 2  A square and a rectangle have all their angles measuring 90Â°. So, the angles of a square and a rectangle are Congruent Angles.  Congruent Angles Figures have the same shape and size.