According to Math Is Fun, "a cross section is the shape you get when cutting straight across an object." For example, if you were to "cut" through the middle of a cylinder, you would have a circle. To determine the volume of a cross-section shape you will need to calculate the end area volume. Although this may sound a bit confusing, the formula is actually quite simple. To find the end area volume, you need to first know the length and the areas of the shape.
Write down the equation for end area volume: Volume = length x 1/2 (A1 + A2) cubic meter
Fill in the variables that are known. For this example, let's say that you need to find the volume (V) of two cross sections with length (L) 40 m and two areas (A1 and A2) of 110 m^2 and 135 m^2, respectively: V = 40 x 1/2 (110 + 135)
Add the two areas (A1 + A2) together: V = 40 x 1/2 (245)
Multiply 1/2 and 245 together: V = 40 x 122.5
Multiply 40 and 122.5 together: V = 4,900 m^3