Find the area of the triangle or quadrilateral.
https://homework.russianschool.com/resource?key=6311i8hp7kav
this is a trapezoid. The formula for the volume of a trapezoid is (base1 + base2)/2*height = (8+13)/2*4
canceling out twos, we get (8+13)*2 = 16 + 26 = 42.
