Area

Learning OutcomesI can find the area of the following 2D shapes. Rectangle TriangleTrapeziumCircle

S3 BLOCK 8 Area and volume

Area

Area is the size of a surface.

It is the amount of space inside the boundary of a 2D shape.

The Area of Rectangle

For a rectangle,

Area = length x breadth

length

breadth

The Area of a Circle

For a circle,

Note: is

is the radiusRadius, the distance from the centre of the circle to the outside edge.

𝑟

The Area of a Triangle

For a triangle,

Note: is the perpendicular height is the base

h

𝑏

The Area of a Trapezium

𝐴𝑟𝑒𝑎=12h(𝑎+𝑏)

h

a

bFor a trapezium,

Note: is the perpendicular height

Example 1: Calculate the area

Height is 7 cmBase is 6 cm

Example 2: Calculate the area

Example 2: Calculate the area

h=5 𝑎=8 b=4

𝐴=12×5(8+4)

𝐴=0 ∙5×5×12

𝐴=30𝑐𝑚2

Example 3: Calculate the area

Example 3: Calculate the area

Area of square

A = 64

Area of semi circle

The diameter is 8 mThe radius is 4 m

Total = 89·12