Area of Irregular Figures (Jump to: Lecture | Video )

Figure 1.

Above we have an irregular figure.

To find the area of an irregular figure, first split the figure into more manageable objects that you�re already familiar with.

Figure 2.

Here, we've split the figure into two rectangles and a half circle. We know how to find the areas of all these objects.

First, we find the area of rectangle 1:

Area of Rectangle 1 = Base * Height = 4 * 10 = 40

Next, we find the area of rectangle 2:

Area of Rectangle 2 = Base * Height = 3 * (8 - 4) = 12

Last, we find the area of the circle. Because it's a half-circle, we multiply the area by (1/2).

Area of Circle = (1/2)(3.14)r^2 = (1/2)(3.14)1^2 = 1.57

We add the three areas together to find our total area:

Total Area = 40 + 12 + 1.57 = 53.57