Triangle Relationships
Geom · Unit 5
Triangle Angle-Sum Theorem
180° proved, not memorized
Curriculum standard — Understand stage of the Thinking Ladder
Concept first
Triangle Angle-Sum Theorem begins with meaning — what it is and why it holds — before any procedure. The structure comes first; computation follows.
Definition
Triangle Angle-Sum Theorem
The precise meaning of this topic, stated in mathematical terms.
A plain-language restatement so the definition is understood, not just memorized.
Three pathways, one topic