## Core concept 6.2

## Perimeter, area and volume

6.2.1.1 Use the properties of a range of polygons to deduce their perimeters

6.2.1.2 Recognise that there is constant multiplicative relationship (π) between the diameter and circumference of a circle

6.2.1.3 Use the relationship C = πd to calculate unknown lengths in contexts involving the circumference of circles

6.2.2.1* Derive and use the formula for the area of a trapezium

6.2.2.2 Understand that the areas of composite shapes can be found in different ways

6.2.2.3* Understand the derivation of, and use the formula for, the area of a circle

6.2.2.4 Solve area problems of composite shapes involving whole and/or part circles, including finding the radius or diameter given the area

6.2.2.5* Understand the concept of surface area and find the surface area of 3D shapes in an efficient way

### 6.2.2.3 Understand the derivation of, and use the formula for, the area of a circle

●Understand the approximate relationship between the area of a circle and the square of its radius.

●Appreciate that the formula for the area of a circle can be derived from prior knowledge.

●Calculate the area of a circle and appreciate the effect of taking different values of 𝜋 .

●Solve problems involving calculating the area of a circle in context.

### 6.2.2.5 Understand the concept of surface area and find the surface area of 3D shapes in an efficient way

●Understand that prisms can have a different number of faces and, therefore, the surface area can be the sum of a different number of areas.

●Understand that the surface area of a prism is the sum of the area of all the faces and not just the visible ones.

●Understand how to use the correct dimensions to calculate the area of 2D shapes.

●There is no standard formula for calculating the surface area of a prism.

●The units of surface area are squared.

●Solve familiar and unfamiliar problems, including real-life applications.

●Solve problems where there is more than one answer and there are elements of experimentation, investigation, checking, reasoning, proof, etc.

6.2.3.1 Be aware that all prisms have two congruent polygonal parallel faces (bases) with parallelogram faces joining the corresponding vertices of the bases

6.2.3.2 Use the constant cross-sectional area property of prisms and cylinders to determine their volume