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Angle names
<90° acute · 90° right · 90–180° obtuse · 180° straight.
30° 90° 120° 180°
Angles
📖 Study · Angles (Grade 5)
Angles (Grade 5)
Right (90°), straight (180°), full turn (360°). Measure with a protractor.
🎯 What you'll learn
- ✓Identify acute / right / obtuse
- ✓Use a protractor
- ✓Sum of angles in a triangle
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Triangle angles
Three angles in any triangle add up to 180°.
△ a + b + c = 180°
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Protractor
A half-circle ruler with degree marks. Line up the zero with one ray.
📐
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Quadrilateral angles
All four angles add up to 360°.
□ ∑ = 360°
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Where we use angles
Architecture, sports throws, telescopes — angles everywhere.
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