Engage your 5th grade students with this interactive notebook activity and extension mini-lesson designed to enhance understanding of triangle classification by sides and angles. Perfect for core instruction and differentiation for advanced, gifted, or accelerated learners!

This resource aligns with enVision Topic 16.1 and supports CCSS 5.G while previewing 7.G.B.5.

• Leave a review – Your feedback helps me improve and create more resources!

• Follow my store – Be the first to know when I upload new freebies and resources!

• Check out my other products – I create engaging, no-prep activities for upper elementary!

What's Included:

✅ Interactive Notebook Page:

• Definitions and visual notes for:
  • Equilateral Triangle
  • Isosceles Triangle
  • Scalene Triangle

• Angle Classification:
  • Right Triangle – One 90° angle
    
  • Acute Triangle – All angles < 90°
    
  • Obtuse Triangle – One angle > 90°
    

✅ Mini Enrichment Lesson (Gifted/Accelerated Learners):

• Objective: Understand that the sum of a triangle's angles is always 180°
  
• Visual Examples (e.g., 50° + 70° + ? = 180° → ? = 60°)
  
• Student Practice:
  • Find missing angles in right, acute, and obtuse triangles

• Challenge Problems:
  • Multi-step logic tasks (e.g., If angle A is twice angle B…)
    
• Concepts Covered:
  • Triangle Sum Theorem
    
  • Introduction to algebraic thinking
    
  • Logical reasoning with geometric figures
    

✅ Printable Worksheet: “Find the Missing Angle”

• 8 practice problems with two given angles
  
• Students calculate the third angle using the 180° rule