Chapter 16.2
Isosceles and equilateral triangles
What You'll Learn
Identify equilateral triangles by recognizing three equal sides and three 60-degree angles
Recognize isosceles triangles and apply the property that two sides and two angles are equal
Apply the triangle sum theorem to find missing angles in triangles
Use congruent sides to set up and solve equations for unknown variables
Prove triangle congruence using side-angle-side (SAS) and reflexive property
What You'll Practice
1
Finding missing angles in equilateral triangles
2
Solving for variables using equal side lengths in isosceles triangles
3
Determining unknown angles using the 180-degree triangle sum
4
Proving triangles are isosceles using congruence theorems
Why This Matters
Mastering isosceles and equilateral triangles builds your foundation for geometry proofs, trigonometry, and real-world applications like engineering and architecture. These special triangles appear throughout higher math, and recognizing their properties helps you solve complex problems quickly.
This Unit Includes
5 Video lessons
Skills
Isosceles Triangles
Equilateral Triangles
Triangle Sum Theorem
Congruence
Angle Properties
Algebraic Reasoning
Geometric Proofs
