Subject: The area of a quadrilateral
Name: Georgina
Who are you: Student

I would really like to know and be shown how to figure out the area of a quadrilateral. I already know that it is side x matching height but i need to be shown what to do.
Could you please help?

Hi Georgina,

1. If you know the lengths of the four sides and the length of a diagonal you can see the quadrilateral as two triangles and find the area as the sum of the areas of the two triangles.
   
   
2. If you know the lengths of the four sides and one of the angles then you can use the law of cosines to find the length of a diagonal and proceed as in 1.
   
   
3. If you only know the lengths of the four sides then you can't find the area as the lengths of the sides is not enough information to determine the shape.

Penny