Area of 2D and 3D Shapes

Area of Triangles and Composite Shapes

Composite Area of 2D Shapes

Surface Area of a Cube and Cuboid

Surface Area of Prisms

Prerequisite Knowledge

• Derive and apply formulae to calculate and solve problems involving: perimeter and area of triangles, parallelograms, trapezia, volume of cuboids (including cubes) and other prisms
• Calculate and solve problems involving: perimeters of 2-D shapes and composite shapes.

Key Concepts

• The area of a triangle is the product of its perpendicular height and base divided by two.  Students often forget to divide by two.
• To find the area of a composite shapes students should break it down into its individual components.
• When identifying individual components of a composite shape students tend to look for triangles and rectangles rather than trapezia and parallelograms.
• To find the surface of a cube or cuboid students could draw the net and work out the composite area.
• More able students could derive the formula for the surface are of a cuboid.

Working mathematically

Develop fluency

• Use language and properties precisely to analyse 2-D and 3-D shapes

Reason mathematically

• Begin to reason deductively in geometry,

Solve problems

• Select appropriate concepts, methods and techniques to apply to unfamiliar and non-routine problems.

Subject Content

Shape

• Derive and apply formulae to calculate and solve problems involving: perimeter and area of triangles, parallelograms, trapezia, volume of cuboids (including cubes) and other prisms
• Calculate and solve problems involving: perimeters of 2-D shapes and composite shapes.