Geometrical Reasoning, Shapes and Measurements

Circle Vocabulary Radius (r): the distance from the centre of a circle to its edge. Diameter (d): the distance across a circle through its centre - always twice…

Very Small and Very Large Units Some quantities are measured using very small or very large units, depending on their size. Recognising the right unit - and…

What is a Prism? A prism is a 3D shape with two identical, parallel end faces (the cross-section ), connected by flat side faces. The cross-section stays…

What is Surface Area? Surface area is the total area of every face of a 3D shape, added together. A net - the shape unfolded flat - is a useful way to see and…

What is a Plane of Symmetry? A 2D shape has a line of symmetry; a 3D shape has a plane of symmetry instead - a flat surface that slices the shape into two…

Polygon Vocabulary Polygon: a 2D shape made entirely of straight sides. Regular polygon: all sides and all angles equal. Irregular polygon: sides and/or angles…

Angles on a Line and Around a Point Angles on a straight line sum to 180°. Angles around a point sum to 360°. Vertically opposite angles (formed where two lines…

What is Pythagoras' Theorem? For any right-angled triangle , the square of the hypotenuse (the longest side, opposite the right angle) equals the sum of the…

Construction Tools and Conventions A construction uses only a pair of compasses (for arcs and circles of a fixed radius) and a straightedge (for drawing…