The height divides the shape into 2 parts : a trapezoid and a right-angled triangle.
A(trapezoid) = [(a+b)h]/2, where a;b;h are the length, width and height respectively.
-> A(trapezoid) = [(15.3+17.4) x 6]/2 = 98.1 (yd2)
A(triangle) = lh/2, where l is the base.
-> A(triangle) = 2.1 x 6 : 2 = 6.3 (yd2)
So, the area of the figure is 98.1 + 6.3 = 104.4 (yd2)