Angles & 2D Shapes

Overview

Angles measure turn, and in Year 7 students learn the angle facts that let them reason about shapes: angles on a straight line, angles at a point, and angles in a triangle. They also classify triangles and quadrilaterals by their sides and angles. Setting out clear geometric reasoning — giving a reason for every step — is a habit examiners reward.

What You Will Learn

• Use the fact that angles on a straight line add up to 180°
• Use the fact that angles at a point add up to 360°
• Use the fact that angles in a triangle add up to 180°
• Classify triangles as equilateral, isosceles, scalene or right-angled
• Classify quadrilaterals and describe their properties

Key Vocabulary

Common Mistakes to Avoid

• Assuming a triangle is isosceles or right-angled just because it looks that way in the diagram
• Forgetting to give a reason for each step of working
• Mixing up angles on a line (180°) with angles at a point (360°)
• Measuring from the wrong scale on a protractor

Frequently Asked Questions