Areas and perimeters

AREA

- Square:

- Rectangle: A = b·h = w·l

- Triangle:          

  

- Parallelogram: A = b·h

  

- Rhombus:

     

- Trapezium:  

- Other polygons:

   P = perimeter,  a = apothem

    

- Cirumference:  L = 2·π·r

- Circle: A = π·r²

   

PERIMETER

The perimeter of a polygon is the length of the boundary line of a shape.

For example:

- Square: P = 4 · s

- Rectangle: P = 2b + 2h

- Triangle: P = a + b + c

 

 

 

Exercise: calculate the area and perimeter of these figures:

a) The red zone of this traffic signal   

 b)

 

 

 

 

Solutions: a) A = 3626.54 cm², P = 431.33 cm; b) A = 64.56 m², P = 33.44 m