Page 99 - Knowledge Organiser Yr7 24-25

Knowledge Base: Mathematics TOPIC 8: Area and Perimeter Year 7 | Spring Term 2
By the end of this topic you should be able to:
• Calculate the perimeter of a shape
• Calculate the area of a shape in squares
• Calculate the perimeter and area of a rectangle and a shape made from rectangles
• Calculate the area of a triangle
• Calculate the area of a parallelogram and trapezium
• Recognize the properties of a circle
• Calculate the circumference and area of a circle
Language
Meaning
Example
Perimeter
The distance around the edge of a shape
The perimeter of a square with lengths 5cm is 20 cm
Area
The space inside a 2D shape
The area of a square with lengths 5cm is 25 cm2
Rectangle
A four sided shape with 4 right angles and two pairs of equal length sides
The shape of this page is a rectangle
Triangle
A three sided shape
Parallelogram
A four sided shape with 2 pairs of parallel sides
Trapezium
A four sided shape with 1 pair of parallel sides
The cross section of a trough is a trapezium
Circumference
The distance around a circle
Diameter
The distance across a circle through the centre
Radius
The distance from the centre of a circle to its circumference
Formulae to remember:
Area of a rectangle / square Area of a triangle
Area of a parallelogram Always use the vertical height! Area of a trapezium
(A and B are the parallel sides) Circumference of a circle
Area of a circle
𝒃 × 𝒉
𝟏/𝟐 𝒃 × 𝒉 𝒃 × 𝒉
𝟏/𝟐 (𝑨 + 𝑩) × 𝒉
𝟐 × 𝝅 × 𝒓 𝝅 × 𝒓𝟐
Worked examples
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