The area of even quadrilaterals is defined by set formulas students memorize in late elementary and early middle school. Uneven quadrilaterals are more difficult to calculate, but you can do so by dividing them into even shapes for which you know the formulas.
Area of a Parallelogram
Draw a rectangle using the two straight lines as the sides. Calculate the areas of the rectangle and the two triangles formed outside the rectangle. Find the area by adding the areas of all three shapes. If the rectangle measures 4 inches square and each triangle has an area of 2 square inches, the volume is 8 square inches.
Area of a Kite (Rhombus)
Draw a two straight lines to connect the opposite corners of the kite to each other. This will divide the kite into four right triangles. The area of the rhombus is the total area of all four triangles. In a rhombus containing two triangles of 4 square inches, and two triangles of 6 square inches, the total area would be 20 square inches.