# Area of 2D Shapes

Scheme of work: GCSE Higher: Year 9: Term 1: Area of 2D Shapes

#### Prerequisite Knowledge

• Know and apply formulae to calculate the area of rectangles.
• Calculate the perimeters of 2D shapes, including composite shapes;
• Compare and order lengths, mass, volume / capacity and record the results using >, < and =
• Measure, compare, add and subtract: lengths (m/cm/mm); mass(kg/g); volume/capacity (l/ml)
• Identify and apply circle definitions and properties, including: centre, radius, chord, diameter, circumference, tangent, arc, sector and segment

#### Success Criteria

• Know and apply formulae to calculate: the area of triangles, parallelograms and trapezia;
• Know the formulae: circumference of a circle = 2πr = πd, area of a circle = πr2; calculate: perimeters of 2D shapes, including circles; areas of circles and composite shapes;
• Calculate arc lengths, angles and areas of sectors of circles

#### Key Concepts

• Demonstrate a triangle as being half a rectangle, so students know to use the perpendicular height in their calculation. Demonstrate a parallelogram as having an equal area to a rectangle.
• To calculate the area of composite rectilinear shapes have students break them up in different ways.
• A sector is a fraction of 360° of the entire circle.

#### Common Misconceptions

• Students often confuse area and perimeter.
• When calculating the area of a triangle or parallelogram students tend to use the slanted height rather than the correct perpendicular height.
• Arc length and area of a sector are often rounded incorrectly. Encourage students to evaluate as a multiple of pi and calculate the decimal at the end.

## Area of 2D Shapes Resources

### Mr Mathematics Blog

#### Planes of Symmetry in 3D Shapes

Planes of Symmetry in 3D Shapes for Key Stage 3/GCSE students.

Use isometric paper for hands-on learning and enhanced understanding.

#### GCSE Trigonometry Skills & SOH CAH TOA Techniques

Master GCSE Math: Get key SOH-CAH-TOA tips, solve triangles accurately, and tackle area tasks. Ideal for students targeting grades 4-5.

#### Regions in the Complex Plane

Explore Regions in the Complex Plane with A-Level Further Maths: inequalities, Argand diagrams, and geometric interpretations.