GoblinsCreate Account
Standards/Math/Virgin Islands/8.G.A.5

8.G.A.5

8.G.A Understand congruence and similarity using physical models, transparencies, or geometry software.
8.G.A.1
8.G.A.2
8.G.A.3
8.G.A.4
8.G.A.5

Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.

Khan Academy Resources
Triangle angles reviewFinding angle measures using trianglesFind angles in trianglesAngle relationships with parallel linesEquation practice with anglesEquation practice with angle additionFind angles in isosceles trianglesAngles, parallel lines, & transversalsAngles in a triangle sum to 180° proofWorked example: Triangle angles (intersecting lines)Worked example: Triangle angles (diagram) Triangle exterior angle exampleIsosceles & equilateral triangles problemsMeasures of angles formed by a transversalMissing angles with a transversal
Goblins

1-on-1 AI tutoring aligned to 8.G.A.5. Instant help for students, real-time insights for teachers.

Used in classrooms by 100,000+ students at Baltimore County, Plano ISD, Deer Valley USD, KIPP, and districts nationwide.

Free for teachers, forever →

Resources

Privacy PolicyTerms of ServiceCareersTeacher LoginStudent Login

Communities

Access 4 Learning Community, Student Data Privacy Consortium
Goblins

© 2023-2026 Aha Moments, Inc.