Finding x with Triangle Angles
aligned to Kansas Math Standard 8.g.5
Learning Objective
I can determine the value of x using angle relationships in triangles using both interior and exterior angles.
Lesson Flow
Watch Video
Interior and Exterior Angles of Triangles
Ryne Roper
Guided Notes
Key concepts students will learn:
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Interior angles are inside a polygon, while exterior angles are outside and adjacent to the interior angles.
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The sum of the measures of the interior angles of a triangle is always 180 degrees; this is known as the triangle sum theorem.
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An exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.
Practice
12 questions • Multiple choice & Short answer
Exit Ticket
“In a triangle, two interior angles measure 25° and 65°. What is the measure of the third interior angle, x?”
Teacher Guide
Get the complete package:
- Answer keys for all questions
- Differentiation strategies
- Extension activities
- Printable student handouts
