How can i find the area of a quadrilateral?

Please explain step by step

thank you

 

Hi,

Join two vertices so that the quadrilateral is divided into two triangles.

The area of the quadrilateral is then the sum of the areas of the two triangles. The area of each triangle you can find using the expression

triangle area =  1/2 base x height

or by using

Heron's formula.

Penny