lesson
Proving the Base Angles Theorem
Construct a two-column proof that the base angles of an isosceles triangle are congruent using auxiliary segments.
Updated 1 month ago · 4 views
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This lesson is part of a track
Public learning track
Triangle Angle Theorems and Isosceles Triangles
8 lessons
Goal
Prove and apply the triangle angle sum theorem, exterior angle theorem, and base angles theorem, and use isosceles triangle properties to solve for unknown angles and sides.
8 lessons
0 of 8 done
- Proving the Triangle Angle Sum TheoremUp next
- Finding the Third Angle of a Triangle Given Two AnglesNot started yet
- Finding Missing Angles Using the Exterior Angle TheoremNot started yet
- Base Angles Theorem: Isosceles Triangle PropertiesNot started yet
- Proving the Base Angles TheoremYou are here
- Converse of the Base Angles TheoremNot started yet
- Isosceles Triangle: Finding All Sides From PerimeterNot started yet
- Isosceles Triangle: Given Perimeter and One SideNot started yet
Learning standards covered
111.41(b)(6)(D)Texas Essential Knowledge and Skills (TEKS) · Math · 10th Gradeverify theorems about the relationships in triangles, including proof of the Pythagorean Theorem, the sum of interior angles, base angles of isosceles triangles, midsegments, and medians, and apply these relationships to solve problems; and
Open Global Standard:OGM.11.GEO.4
111.41(b)(1)(G)Texas Essential Knowledge and Skills (TEKS) · Math · 10th Gradedisplay, explain, and justify mathematical ideas and arguments using precise mathematical language in written or oral communication.
Open Global Standard:OGM.11.GEO.1
OGM.11.GEO.4OGM.11.GEO.1