Isosceles & Equilateral Triangles Theorems Find x & Angles
by Making Algebra Fun by Angela Dougher © 2026
Premier Publisher
Price: $2 USD
Subjects: midSchoolGeometry,highSchoolGeometry,congruence,geometricalFigures
Grades: 8,9,10
Description
Students practice the Isosceles Triangle Theorem, its converse, and equilateral triangle properties with 15 self-checking digital task cards. Problems progress from finding a missing base or vertex angle to setting congruent sides or angles equal and solving for x. Skills covered: • Base angles of an isosceles triangle are congruent • Finding vertex and base angles with the Triangle Angle Sum Theorem • Equilateral triangles: congruent sides and 60° angles • Solving for x with congruent sides and congruent angles • Right isosceles triangles • Exterior angles of isosceles triangles • Converse of the Isosceles Triangle Theorem • Perimeter of an isosceles triangle • Two-step problem: solve for x, then find an angle measure Students type a numeric answer on every card, so the deck works for independent practice, homework, stations, review, and sub plans. Each card includes alt text for screen reader users. "Problems and alt text were created with the help of AI (Claude by Anthropic) and reviewed by the author for accuracy."